ui-log: Implement support for commit graphs

Teach CGit to print an ASCII art commit graph to the left of the commit
message, similar to 'git log --graph'. The graph adds extra lines (table
rows) to the log when needed to add/remove/shuffle edges in the graph.

When 'showmsg' is enabled, the graph is automatically padded to account
for the extra lines added by the commit message/notes.

This feature is controlled by a new config variable: "enable-commit-graph"
(disabled by default), and individual repos can control it by setting
"repo.enable-commit-graph".

Signed-off-by: Johan Herland <johan@herland.net>
Signed-off-by: Lars Hjemli <hjemli@gmail.com>

6 files changed, 112 insertions, 23 deletions

diff --git a/cgit.c b/cgit.c
index 412fbf0..53ab68d 100644
--- a/cgit.c
+++ b/cgit.c
@@ -1,335 +1,339 @@
 /* cgit.c: cgi for the git scm
  *
  * Copyright (C) 2006 Lars Hjemli
  * Copyright (C) 2010 Jason A. Donenfeld <Jason@zx2c4.com>
  *
  * Licensed under GNU General Public License v2
  *   (see COPYING for full license text)
  */
 
 #include "cgit.h"
 #include "cache.h"
 #include "cmd.h"
 #include "configfile.h"
 #include "html.h"
 #include "ui-shared.h"
 #include "ui-stats.h"
 #include "scan-tree.h"
 
 const char *cgit_version = CGIT_VERSION;
 
 void add_mimetype(const char *name, const char *value)
 {
         struct string_list_item *item;
 
         item = string_list_insert(&ctx.cfg.mimetypes, xstrdup(name));
         item->util = xstrdup(value);
 }
 
 struct cgit_filter *new_filter(const char *cmd, int extra_args)
 {
         struct cgit_filter *f;
 
         if (!cmd || !cmd[0])
                 return NULL;
 
         f = xmalloc(sizeof(struct cgit_filter));
         f->cmd = xstrdup(cmd);
         f->argv = xmalloc((2 + extra_args) * sizeof(char *));
         f->argv[0] = f->cmd;
         f->argv[1] = NULL;
         return f;
 }
 
 static void process_cached_repolist(const char *path);
 
 void repo_config(struct cgit_repo *repo, const char *name, const char *value)
 {
         if (!strcmp(name, "name"))
                 repo->name = xstrdup(value);
         else if (!strcmp(name, "clone-url"))
                 repo->clone_url = xstrdup(value);
         else if (!strcmp(name, "desc"))
                 repo->desc = xstrdup(value);
         else if (!strcmp(name, "owner"))
                 repo->owner = xstrdup(value);
         else if (!strcmp(name, "defbranch"))
                 repo->defbranch = xstrdup(value);
         else if (!strcmp(name, "snapshots"))
                 repo->snapshots = ctx.cfg.snapshots & cgit_parse_snapshots_mask(value);
+        else if (!strcmp(name, "enable-commit-graph"))
+                repo->enable_commit_graph = ctx.cfg.enable_commit_graph * atoi(value);
         else if (!strcmp(name, "enable-log-filecount"))
                 repo->enable_log_filecount = ctx.cfg.enable_log_filecount * atoi(value);
         else if (!strcmp(name, "enable-log-linecount"))
                 repo->enable_log_linecount = ctx.cfg.enable_log_linecount * atoi(value);
         else if (!strcmp(name, "enable-remote-branches"))
                 repo->enable_remote_branches = atoi(value);
         else if (!strcmp(name, "enable-subject-links"))
                 repo->enable_subject_links = atoi(value);
         else if (!strcmp(name, "max-stats"))
                 repo->max_stats = cgit_find_stats_period(value, NULL);
         else if (!strcmp(name, "module-link"))
                 repo->module_link= xstrdup(value);
         else if (!strcmp(name, "section"))
                 repo->section = xstrdup(value);
         else if (!strcmp(name, "readme") && value != NULL) {
                 repo->readme = xstrdup(value);
         } else if (ctx.cfg.enable_filter_overrides) {
                 if (!strcmp(name, "about-filter"))
                         repo->about_filter = new_filter(value, 0);
                 else if (!strcmp(name, "commit-filter"))
                         repo->commit_filter = new_filter(value, 0);
                 else if (!strcmp(name, "source-filter"))
                         repo->source_filter = new_filter(value, 1);
         }
 }
 
 void config_cb(const char *name, const char *value)
 {
         if (!strcmp(name, "section") || !strcmp(name, "repo.group"))
                 ctx.cfg.section = xstrdup(value);
         else if (!strcmp(name, "repo.url"))
                 ctx.repo = cgit_add_repo(value);
         else if (ctx.repo && !strcmp(name, "repo.path"))
                 ctx.repo->path = trim_end(value, '/');
         else if (ctx.repo && !prefixcmp(name, "repo."))
                 repo_config(ctx.repo, name + 5, value);
         else if (!strcmp(name, "readme"))
                 ctx.cfg.readme = xstrdup(value);
         else if (!strcmp(name, "root-title"))
                 ctx.cfg.root_title = xstrdup(value);
         else if (!strcmp(name, "root-desc"))
                 ctx.cfg.root_desc = xstrdup(value);
         else if (!strcmp(name, "root-readme"))
                 ctx.cfg.root_readme = xstrdup(value);
         else if (!strcmp(name, "css"))
                 ctx.cfg.css = xstrdup(value);
         else if (!strcmp(name, "favicon"))
                 ctx.cfg.favicon = xstrdup(value);
         else if (!strcmp(name, "footer"))
                 ctx.cfg.footer = xstrdup(value);
         else if (!strcmp(name, "head-include"))
                 ctx.cfg.head_include = xstrdup(value);
         else if (!strcmp(name, "header"))
                 ctx.cfg.header = xstrdup(value);
         else if (!strcmp(name, "logo"))
                 ctx.cfg.logo = xstrdup(value);
         else if (!strcmp(name, "index-header"))
                 ctx.cfg.index_header = xstrdup(value);
         else if (!strcmp(name, "index-info"))
                 ctx.cfg.index_info = xstrdup(value);
         else if (!strcmp(name, "logo-link"))
                 ctx.cfg.logo_link = xstrdup(value);
         else if (!strcmp(name, "module-link"))
                 ctx.cfg.module_link = xstrdup(value);
         else if (!strcmp(name, "strict-export"))
                 ctx.cfg.strict_export = xstrdup(value);
         else if (!strcmp(name, "virtual-root")) {
                 ctx.cfg.virtual_root = trim_end(value, '/');
                 if (!ctx.cfg.virtual_root && (!strcmp(value, "/")))
                         ctx.cfg.virtual_root = "";
         } else if (!strcmp(name, "nocache"))
                 ctx.cfg.nocache = atoi(value);
         else if (!strcmp(name, "noplainemail"))
                 ctx.cfg.noplainemail = atoi(value);
         else if (!strcmp(name, "noheader"))
                 ctx.cfg.noheader = atoi(value);
         else if (!strcmp(name, "snapshots"))
                 ctx.cfg.snapshots = cgit_parse_snapshots_mask(value);
         else if (!strcmp(name, "enable-filter-overrides"))
                 ctx.cfg.enable_filter_overrides = atoi(value);
         else if (!strcmp(name, "enable-gitweb-owner"))
                 ctx.cfg.enable_gitweb_owner = atoi(value);
         else if (!strcmp(name, "enable-index-links"))
                 ctx.cfg.enable_index_links = atoi(value);
+        else if (!strcmp(name, "enable-commit-graph"))
+                ctx.cfg.enable_commit_graph = atoi(value);
         else if (!strcmp(name, "enable-log-filecount"))
                 ctx.cfg.enable_log_filecount = atoi(value);
         else if (!strcmp(name, "enable-log-linecount"))
                 ctx.cfg.enable_log_linecount = atoi(value);
         else if (!strcmp(name, "enable-remote-branches"))
                 ctx.cfg.enable_remote_branches = atoi(value);
         else if (!strcmp(name, "enable-subject-links"))
                 ctx.cfg.enable_subject_links = atoi(value);
         else if (!strcmp(name, "enable-tree-linenumbers"))
                 ctx.cfg.enable_tree_linenumbers = atoi(value);
         else if (!strcmp(name, "max-stats"))
                 ctx.cfg.max_stats = cgit_find_stats_period(value, NULL);
         else if (!strcmp(name, "cache-size"))
                 ctx.cfg.cache_size = atoi(value);
         else if (!strcmp(name, "cache-root"))
                 ctx.cfg.cache_root = xstrdup(expand_macros(value));
         else if (!strcmp(name, "cache-root-ttl"))
                 ctx.cfg.cache_root_ttl = atoi(value);
         else if (!strcmp(name, "cache-repo-ttl"))
                 ctx.cfg.cache_repo_ttl = atoi(value);
         else if (!strcmp(name, "cache-scanrc-ttl"))
                 ctx.cfg.cache_scanrc_ttl = atoi(value);
         else if (!strcmp(name, "cache-static-ttl"))
                 ctx.cfg.cache_static_ttl = atoi(value);
         else if (!strcmp(name, "cache-dynamic-ttl"))
                 ctx.cfg.cache_dynamic_ttl = atoi(value);
         else if (!strcmp(name, "about-filter"))
                 ctx.cfg.about_filter = new_filter(value, 0);
         else if (!strcmp(name, "commit-filter"))
                 ctx.cfg.commit_filter = new_filter(value, 0);
         else if (!strcmp(name, "embedded"))
                 ctx.cfg.embedded = atoi(value);
         else if (!strcmp(name, "max-atom-items"))
                 ctx.cfg.max_atom_items = atoi(value);
         else if (!strcmp(name, "max-message-length"))
                 ctx.cfg.max_msg_len = atoi(value);
         else if (!strcmp(name, "max-repodesc-length"))
                 ctx.cfg.max_repodesc_len = atoi(value);
         else if (!strcmp(name, "max-blob-size"))
                 ctx.cfg.max_blob_size = atoi(value);
         else if (!strcmp(name, "max-repo-count"))
                 ctx.cfg.max_repo_count = atoi(value);
         else if (!strcmp(name, "max-commit-count"))
                 ctx.cfg.max_commit_count = atoi(value);
         else if (!strcmp(name, "project-list"))
                 ctx.cfg.project_list = xstrdup(expand_macros(value));
         else if (!strcmp(name, "scan-path"))
                 if (!ctx.cfg.nocache && ctx.cfg.cache_size)
                         process_cached_repolist(expand_macros(value));
                 else if (ctx.cfg.project_list)
                         scan_projects(expand_macros(value),
                                       ctx.cfg.project_list, repo_config);
                 else
                         scan_tree(expand_macros(value), repo_config);
         else if (!strcmp(name, "section-from-path"))
                 ctx.cfg.section_from_path = atoi(value);
         else if (!strcmp(name, "source-filter"))
                 ctx.cfg.source_filter = new_filter(value, 1);
         else if (!strcmp(name, "summary-log"))
                 ctx.cfg.summary_log = atoi(value);
         else if (!strcmp(name, "summary-branches"))
                 ctx.cfg.summary_branches = atoi(value);
         else if (!strcmp(name, "summary-tags"))
                 ctx.cfg.summary_tags = atoi(value);
         else if (!strcmp(name, "side-by-side-diffs"))
                 ctx.cfg.ssdiff = atoi(value);
         else if (!strcmp(name, "agefile"))
                 ctx.cfg.agefile = xstrdup(value);
         else if (!strcmp(name, "renamelimit"))
                 ctx.cfg.renamelimit = atoi(value);
         else if (!strcmp(name, "remove-suffix"))
                 ctx.cfg.remove_suffix = atoi(value);
         else if (!strcmp(name, "robots"))
                 ctx.cfg.robots = xstrdup(value);
         else if (!strcmp(name, "clone-prefix"))
                 ctx.cfg.clone_prefix = xstrdup(value);
         else if (!strcmp(name, "local-time"))
                 ctx.cfg.local_time = atoi(value);
         else if (!prefixcmp(name, "mimetype."))
                 add_mimetype(name + 9, value);
         else if (!strcmp(name, "include"))
                 parse_configfile(expand_macros(value), config_cb);
 }
 
 static void querystring_cb(const char *name, const char *value)
 {
         if (!value)
                 value = "";
 
         if (!strcmp(name,"r")) {
                 ctx.qry.repo = xstrdup(value);
                 ctx.repo = cgit_get_repoinfo(value);
         } else if (!strcmp(name, "p")) {
                 ctx.qry.page = xstrdup(value);
         } else if (!strcmp(name, "url")) {
                 if (*value == '/')
                         value++;
                 ctx.qry.url = xstrdup(value);
                 cgit_parse_url(value);
         } else if (!strcmp(name, "qt")) {
                 ctx.qry.grep = xstrdup(value);
         } else if (!strcmp(name, "q")) {
                 ctx.qry.search = xstrdup(value);
         } else if (!strcmp(name, "h")) {
                 ctx.qry.head = xstrdup(value);
                 ctx.qry.has_symref = 1;
         } else if (!strcmp(name, "id")) {
                 ctx.qry.sha1 = xstrdup(value);
                 ctx.qry.has_sha1 = 1;
         } else if (!strcmp(name, "id2")) {
                 ctx.qry.sha2 = xstrdup(value);
                 ctx.qry.has_sha1 = 1;
         } else if (!strcmp(name, "ofs")) {
                 ctx.qry.ofs = atoi(value);
         } else if (!strcmp(name, "path")) {
                 ctx.qry.path = trim_end(value, '/');
         } else if (!strcmp(name, "name")) {
                 ctx.qry.name = xstrdup(value);
         } else if (!strcmp(name, "mimetype")) {
                 ctx.qry.mimetype = xstrdup(value);
         } else if (!strcmp(name, "s")){
                 ctx.qry.sort = xstrdup(value);
         } else if (!strcmp(name, "showmsg")) {
                 ctx.qry.showmsg = atoi(value);
         } else if (!strcmp(name, "period")) {
                 ctx.qry.period = xstrdup(value);
         } else if (!strcmp(name, "ss")) {
                 ctx.qry.ssdiff = atoi(value);
         } else if (!strcmp(name, "all")) {
                 ctx.qry.show_all = atoi(value);
         } else if (!strcmp(name, "context")) {
                 ctx.qry.context = atoi(value);
         } else if (!strcmp(name, "ignorews")) {
                 ctx.qry.ignorews = atoi(value);
         }
 }
 
 char *xstrdupn(const char *str)
 {
         return (str ? xstrdup(str) : NULL);
 }
 
 static void prepare_context(struct cgit_context *ctx)
 {
         memset(ctx, 0, sizeof(*ctx));
         ctx->cfg.agefile = "info/web/last-modified";
         ctx->cfg.nocache = 0;
         ctx->cfg.cache_size = 0;
         ctx->cfg.cache_dynamic_ttl = 5;
         ctx->cfg.cache_max_create_time = 5;
         ctx->cfg.cache_repo_ttl = 5;
         ctx->cfg.cache_root = CGIT_CACHE_ROOT;
         ctx->cfg.cache_root_ttl = 5;
         ctx->cfg.cache_scanrc_ttl = 15;
         ctx->cfg.cache_static_ttl = -1;
         ctx->cfg.css = "/cgit.css";
         ctx->cfg.logo = "/cgit.png";
         ctx->cfg.local_time = 0;
         ctx->cfg.enable_gitweb_owner = 1;
         ctx->cfg.enable_tree_linenumbers = 1;
         ctx->cfg.max_repo_count = 50;
         ctx->cfg.max_commit_count = 50;
         ctx->cfg.max_lock_attempts = 5;
         ctx->cfg.max_msg_len = 80;
         ctx->cfg.max_repodesc_len = 80;
         ctx->cfg.max_blob_size = 0;
         ctx->cfg.max_stats = 0;
         ctx->cfg.module_link = "./?repo=%s&page=commit&id=%s";
         ctx->cfg.project_list = NULL;
         ctx->cfg.renamelimit = -1;
         ctx->cfg.remove_suffix = 0;
         ctx->cfg.robots = "index, nofollow";
         ctx->cfg.root_title = "Git repository browser";
         ctx->cfg.root_desc = "a fast webinterface for the git dscm";
         ctx->cfg.script_name = CGIT_SCRIPT_NAME;
         ctx->cfg.section = "";
         ctx->cfg.summary_branches = 10;
         ctx->cfg.summary_log = 10;
         ctx->cfg.summary_tags = 10;
         ctx->cfg.max_atom_items = 10;
         ctx->cfg.ssdiff = 0;
         ctx->env.cgit_config = xstrdupn(getenv("CGIT_CONFIG"));
         ctx->env.http_host = xstrdupn(getenv("HTTP_HOST"));
         ctx->env.https = xstrdupn(getenv("HTTPS"));
         ctx->env.no_http = xstrdupn(getenv("NO_HTTP"));
         ctx->env.path_info = xstrdupn(getenv("PATH_INFO"));
         ctx->env.query_string = xstrdupn(getenv("QUERY_STRING"));
         ctx->env.request_method = xstrdupn(getenv("REQUEST_METHOD"));
         ctx->env.script_name = xstrdupn(getenv("SCRIPT_NAME"));
         ctx->env.server_name = xstrdupn(getenv("SERVER_NAME"));
         ctx->env.server_port = xstrdupn(getenv("SERVER_PORT"));
         ctx->page.mimetype = "text/html";
@@ -351,384 +355,386 @@ static void prepare_context(struct cgit_context *ctx)
 struct refmatch {
         char *req_ref;
         char *first_ref;
         int match;
 };
 
 int find_current_ref(const char *refname, const unsigned char *sha1,
                      int flags, void *cb_data)
 {
         struct refmatch *info;
 
         info = (struct refmatch *)cb_data;
         if (!strcmp(refname, info->req_ref))
                 info->match = 1;
         if (!info->first_ref)
                 info->first_ref = xstrdup(refname);
         return info->match;
 }
 
 char *find_default_branch(struct cgit_repo *repo)
 {
         struct refmatch info;
         char *ref;
 
         info.req_ref = repo->defbranch;
         info.first_ref = NULL;
         info.match = 0;
         for_each_branch_ref(find_current_ref, &info);
         if (info.match)
                 ref = info.req_ref;
         else
                 ref = info.first_ref;
         if (ref)
                 ref = xstrdup(ref);
         return ref;
 }
 
 static int prepare_repo_cmd(struct cgit_context *ctx)
 {
         char *tmp;
         unsigned char sha1[20];
         int nongit = 0;
 
         setenv("GIT_DIR", ctx->repo->path, 1);
         setup_git_directory_gently(&nongit);
         if (nongit) {
                 ctx->page.title = fmt("%s - %s", ctx->cfg.root_title,
                                       "config error");
                 tmp = fmt("Not a git repository: '%s'", ctx->repo->path);
                 ctx->repo = NULL;
                 cgit_print_http_headers(ctx);
                 cgit_print_docstart(ctx);
                 cgit_print_pageheader(ctx);
                 cgit_print_error(tmp);
                 cgit_print_docend();
                 return 1;
         }
         ctx->page.title = fmt("%s - %s", ctx->repo->name, ctx->repo->desc);
 
         if (!ctx->qry.head) {
                 ctx->qry.nohead = 1;
                 ctx->qry.head = find_default_branch(ctx->repo);
                 ctx->repo->defbranch = ctx->qry.head;
         }
 
         if (!ctx->qry.head) {
                 cgit_print_http_headers(ctx);
                 cgit_print_docstart(ctx);
                 cgit_print_pageheader(ctx);
                 cgit_print_error("Repository seems to be empty");
                 cgit_print_docend();
                 return 1;
         }
 
         if (get_sha1(ctx->qry.head, sha1)) {
                 tmp = xstrdup(ctx->qry.head);
                 ctx->qry.head = ctx->repo->defbranch;
                 ctx->page.status = 404;
                 ctx->page.statusmsg = "not found";
                 cgit_print_http_headers(ctx);
                 cgit_print_docstart(ctx);
                 cgit_print_pageheader(ctx);
                 cgit_print_error(fmt("Invalid branch: %s", tmp));
                 cgit_print_docend();
                 return 1;
         }
         return 0;
 }
 
 static void process_request(void *cbdata)
 {
         struct cgit_context *ctx = cbdata;
         struct cgit_cmd *cmd;
 
         cmd = cgit_get_cmd(ctx);
         if (!cmd) {
                 ctx->page.title = "cgit error";
                 cgit_print_http_headers(ctx);
                 cgit_print_docstart(ctx);
                 cgit_print_pageheader(ctx);
                 cgit_print_error("Invalid request");
                 cgit_print_docend();
                 return;
         }
 
         /* If cmd->want_vpath is set, assume ctx->qry.path contains a "virtual"
          * in-project path limit to be made available at ctx->qry.vpath.
          * Otherwise, no path limit is in effect (ctx->qry.vpath = NULL).
          */
         ctx->qry.vpath = cmd->want_vpath ? ctx->qry.path : NULL;
 
         if (cmd->want_repo && !ctx->repo) {
                 cgit_print_http_headers(ctx);
                 cgit_print_docstart(ctx);
                 cgit_print_pageheader(ctx);
                 cgit_print_error(fmt("No repository selected"));
                 cgit_print_docend();
                 return;
         }
 
         if (ctx->repo && prepare_repo_cmd(ctx))
                 return;
 
         if (cmd->want_layout) {
                 cgit_print_http_headers(ctx);
                 cgit_print_docstart(ctx);
                 cgit_print_pageheader(ctx);
         }
 
         cmd->fn(ctx);
 
         if (cmd->want_layout)
                 cgit_print_docend();
 }
 
 int cmp_repos(const void *a, const void *b)
 {
         const struct cgit_repo *ra = a, *rb = b;
         return strcmp(ra->url, rb->url);
 }
 
 char *build_snapshot_setting(int bitmap)
 {
         const struct cgit_snapshot_format *f;
         char *result = xstrdup("");
         char *tmp;
         int len;
 
         for (f = cgit_snapshot_formats; f->suffix; f++) {
                 if (f->bit & bitmap) {
                         tmp = result;
                         result = xstrdup(fmt("%s%s ", tmp, f->suffix));
                         free(tmp);
                 }
         }
         len = strlen(result);
         if (len)
                 result[len - 1] = '\0';
         return result;
 }
 
 char *get_first_line(char *txt)
 {
         char *t = xstrdup(txt);
         char *p = strchr(t, '\n');
         if (p)
                 *p = '\0';
         return t;
 }
 
 void print_repo(FILE *f, struct cgit_repo *repo)
 {
         fprintf(f, "repo.url=%s\n", repo->url);
         fprintf(f, "repo.name=%s\n", repo->name);
         fprintf(f, "repo.path=%s\n", repo->path);
         if (repo->owner)
                 fprintf(f, "repo.owner=%s\n", repo->owner);
         if (repo->desc) {
                 char *tmp = get_first_line(repo->desc);
                 fprintf(f, "repo.desc=%s\n", tmp);
                 free(tmp);
         }
         if (repo->readme)
                 fprintf(f, "repo.readme=%s\n", repo->readme);
         if (repo->defbranch)
                 fprintf(f, "repo.defbranch=%s\n", repo->defbranch);
         if (repo->module_link)
                 fprintf(f, "repo.module-link=%s\n", repo->module_link);
         if (repo->section)
                 fprintf(f, "repo.section=%s\n", repo->section);
         if (repo->clone_url)
                 fprintf(f, "repo.clone-url=%s\n", repo->clone_url);
+        fprintf(f, "repo.enable-commit-graph=%d\n",
+                repo->enable_commit_graph);
         fprintf(f, "repo.enable-log-filecount=%d\n",
                 repo->enable_log_filecount);
         fprintf(f, "repo.enable-log-linecount=%d\n",
                 repo->enable_log_linecount);
         if (repo->about_filter && repo->about_filter != ctx.cfg.about_filter)
                 fprintf(f, "repo.about-filter=%s\n", repo->about_filter->cmd);
         if (repo->commit_filter && repo->commit_filter != ctx.cfg.commit_filter)
                 fprintf(f, "repo.commit-filter=%s\n", repo->commit_filter->cmd);
         if (repo->source_filter && repo->source_filter != ctx.cfg.source_filter)
                 fprintf(f, "repo.source-filter=%s\n", repo->source_filter->cmd);
         if (repo->snapshots != ctx.cfg.snapshots) {
                 char *tmp = build_snapshot_setting(repo->snapshots);
                 fprintf(f, "repo.snapshots=%s\n", tmp);
                 free(tmp);
         }
         if (repo->max_stats != ctx.cfg.max_stats)
                 fprintf(f, "repo.max-stats=%s\n",
                         cgit_find_stats_periodname(repo->max_stats));
         fprintf(f, "\n");
 }
 
 void print_repolist(FILE *f, struct cgit_repolist *list, int start)
 {
         int i;
 
         for(i = start; i < list->count; i++)
                 print_repo(f, &list->repos[i]);
 }
 
 /* Scan 'path' for git repositories, save the resulting repolist in 'cached_rc'
  * and return 0 on success.
  */
 static int generate_cached_repolist(const char *path, const char *cached_rc)
 {
         char *locked_rc;
         int idx;
         FILE *f;
 
         locked_rc = xstrdup(fmt("%s.lock", cached_rc));
         f = fopen(locked_rc, "wx");
         if (!f) {
                 /* Inform about the error unless the lockfile already existed,
                  * since that only means we've got concurrent requests.
                  */
                 if (errno != EEXIST)
                         fprintf(stderr, "[cgit] Error opening %s: %s (%d)\n",
                                 locked_rc, strerror(errno), errno);
                 return errno;
         }
         idx = cgit_repolist.count;
         if (ctx.cfg.project_list)
                 scan_projects(path, ctx.cfg.project_list, repo_config);
         else
                 scan_tree(path, repo_config);
         print_repolist(f, &cgit_repolist, idx);
         if (rename(locked_rc, cached_rc))
                 fprintf(stderr, "[cgit] Error renaming %s to %s: %s (%d)\n",
                         locked_rc, cached_rc, strerror(errno), errno);
         fclose(f);
         return 0;
 }
 
 static void process_cached_repolist(const char *path)
 {
         struct stat st;
         char *cached_rc;
         time_t age;
         unsigned long hash;
 
         hash = hash_str(path);
         if (ctx.cfg.project_list)
                 hash += hash_str(ctx.cfg.project_list);
         cached_rc = xstrdup(fmt("%s/rc-%8lx", ctx.cfg.cache_root, hash));
 
         if (stat(cached_rc, &st)) {
                 /* Nothing is cached, we need to scan without forking. And
                  * if we fail to generate a cached repolist, we need to
                  * invoke scan_tree manually.
                  */
                 if (generate_cached_repolist(path, cached_rc)) {
                         if (ctx.cfg.project_list)
                                 scan_projects(path, ctx.cfg.project_list,
                                               repo_config);
                         else
                                 scan_tree(path, repo_config);
                 }
                 return;
         }
 
         parse_configfile(cached_rc, config_cb);
 
         /* If the cached configfile hasn't expired, lets exit now */
         age = time(NULL) - st.st_mtime;
         if (age <= (ctx.cfg.cache_scanrc_ttl * 60))
                 return;
 
         /* The cached repolist has been parsed, but it was old. So lets
          * rescan the specified path and generate a new cached repolist
          * in a child-process to avoid latency for the current request.
          */
         if (fork())
                 return;
 
         exit(generate_cached_repolist(path, cached_rc));
 }
 
 static void cgit_parse_args(int argc, const char **argv)
 {
         int i;
         int scan = 0;
 
         for (i = 1; i < argc; i++) {
                 if (!strncmp(argv[i], "--cache=", 8)) {
                         ctx.cfg.cache_root = xstrdup(argv[i]+8);
                 }
                 if (!strcmp(argv[i], "--nocache")) {
                         ctx.cfg.nocache = 1;
                 }
                 if (!strcmp(argv[i], "--nohttp")) {
                         ctx.env.no_http = "1";
                 }
                 if (!strncmp(argv[i], "--query=", 8)) {
                         ctx.qry.raw = xstrdup(argv[i]+8);
                 }
                 if (!strncmp(argv[i], "--repo=", 7)) {
                         ctx.qry.repo = xstrdup(argv[i]+7);
                 }
                 if (!strncmp(argv[i], "--page=", 7)) {
                         ctx.qry.page = xstrdup(argv[i]+7);
                 }
                 if (!strncmp(argv[i], "--head=", 7)) {
                         ctx.qry.head = xstrdup(argv[i]+7);
                         ctx.qry.has_symref = 1;
                 }
                 if (!strncmp(argv[i], "--sha1=", 7)) {
                         ctx.qry.sha1 = xstrdup(argv[i]+7);
                         ctx.qry.has_sha1 = 1;
                 }
                 if (!strncmp(argv[i], "--ofs=", 6)) {
                         ctx.qry.ofs = atoi(argv[i]+6);
                 }
                 if (!strncmp(argv[i], "--scan-tree=", 12) ||
                     !strncmp(argv[i], "--scan-path=", 12)) {
                         /* HACK: the global snapshot bitmask defines the
                          * set of allowed snapshot formats, but the config
                          * file hasn't been parsed yet so the mask is
                          * currently 0. By setting all bits high before
                          * scanning we make sure that any in-repo cgitrc
                          * snapshot setting is respected by scan_tree().
                          * BTW: we assume that there'll never be more than
                          * 255 different snapshot formats supported by cgit...
                          */
                         ctx.cfg.snapshots = 0xFF;
                         scan++;
                         scan_tree(argv[i] + 12, repo_config);
                 }
         }
         if (scan) {
                 qsort(cgit_repolist.repos, cgit_repolist.count,
                         sizeof(struct cgit_repo), cmp_repos);
                 print_repolist(stdout, &cgit_repolist, 0);
                 exit(0);
         }
 }
 
 static int calc_ttl()
 {
         if (!ctx.repo)
                 return ctx.cfg.cache_root_ttl;
 
         if (!ctx.qry.page)
                 return ctx.cfg.cache_repo_ttl;
 
         if (ctx.qry.has_symref)
                 return ctx.cfg.cache_dynamic_ttl;
 
         if (ctx.qry.has_sha1)
                 return ctx.cfg.cache_static_ttl;
 
         return ctx.cfg.cache_repo_ttl;
 }
 
 int main(int argc, const char **argv)
 {
         const char *path;
         char *qry;
         int err, ttl;
 
         prepare_context(&ctx);
         cgit_repolist.length = 0;
         cgit_repolist.count = 0;
         cgit_repolist.repos = NULL;
diff --git a/cgit.css b/cgit.css
index 7a5f423..7600e84 100644
--- a/cgit.css
+++ b/cgit.css
@@ -1,347 +1,352 @@
 body, table, form {
         padding: 0em;
         margin: 0em;
 }
 
 body {
         font-family: sans-serif;
         font-size: 10pt;
         color: #333;
         background: white;
         padding: 4px;
 }
 
 a {
         color: blue;
         text-decoration: none;
 }
 
 a:hover {
         text-decoration: underline;
 }
 
 table {
       border-collapse: collapse;
 }
 
 table#header {
         width: 100%;
         margin-bottom: 1em;
 }
 
 table#header td.logo {
         width: 96px;
 }
 
 table#header td.main {
         font-size: 250%;
         padding-left: 10px;
         white-space: nowrap;
 }
 
 table#header td.main a {
         color: #000;
 }
 
 table#header td.form {
         text-align: right;
         vertical-align: bottom;
         padding-right: 1em;
         padding-bottom: 2px;
         white-space: nowrap;
 }
 
 table#header td.form form,
 table#header td.form input,
 table#header td.form select {
         font-size: 90%;
 }
 
 table#header td.sub {
         color: #777;
         border-top: solid 1px #ccc;
         padding-left: 10px;
 }
 
 table.tabs {
         border-bottom: solid 3px #ccc;
         border-collapse: collapse;
         margin-top: 2em;
         margin-bottom: 0px;
         width: 100%;
 }
 
 table.tabs td {
         padding: 0px 1em;
         vertical-align: bottom;
 }
 
 table.tabs td a {
         padding: 2px 0.75em;
         color: #777;
         font-size: 110%;
 }
 
 table.tabs td a.active {
         color: #000;
         background-color: #ccc;
 }
 
 table.tabs td.form {
         text-align: right;
 }
 
 table.tabs td.form form {
         padding-bottom: 2px;
         font-size: 90%;
         white-space: nowrap;
 }
 
 table.tabs td.form input,
 table.tabs td.form select {
         font-size: 90%;
 }
 
 div.path {
         margin: 0px;
         padding: 5px 2em 2px 2em;
         color: #000;
         background-color: #eee;
 }
 
 div.content {
         margin: 0px;
         padding: 2em;
         border-bottom: solid 3px #ccc;
 }
 
 
 table.list {
         width: 100%;
         border: none;
         border-collapse: collapse;
 }
 
 table.list tr {
         background: white;
 }
 
 table.list tr.logheader {
         background: #eee;
 }
 
 table.list tr:hover {
         background: #eee;
 }
 
 table.list tr.nohover:hover {
         background: white;
 }
 
 table.list th {
         font-weight: bold;
         /* color: #888;
         border-top: dashed 1px #888;
         border-bottom: dashed 1px #888;
         */
         padding: 0.1em 0.5em 0.05em 0.5em;
         vertical-align: baseline;
 }
 
 table.list td {
         border: none;
         padding: 0.1em 0.5em 0.1em 0.5em;
 }
 
+table.list td.commitgraph {
+        font-family: monospace;
+        white-space: pre;
+}
+
 table.list td.logsubject {
         font-family: monospace;
         font-weight: bold;
 }
 
 table.list td.logmsg {
         font-family: monospace;
         white-space: pre;
         padding: 0 0.5em;
 }
 
 table.list td a {
         color: black;
 }
 
 table.list td a.ls-dir {
         font-weight: bold;
         color: #00f;
 }
 
 table.list td a:hover {
         color: #00f;
 }
 
 img {
         border: none;
 }
 
 input#switch-btn {
         margin: 2px 0px 0px 0px;
 }
 
 td#sidebar input.txt {
         width: 100%;
         margin: 2px 0px 0px 0px;
 }
 
 table#grid {
         margin: 0px;
 }
 
 td#content {
         vertical-align: top;
         padding: 1em 2em 1em 1em;
         border: none;
 }
 
 div#summary {
         vertical-align: top;
         margin-bottom: 1em;
 }
 
 table#downloads {
         float: right;
         border-collapse: collapse;
         border: solid 1px #777;
         margin-left: 0.5em;
         margin-bottom: 0.5em;
 }
 
 table#downloads th {
         background-color: #ccc;
 }
 
 div#blob {
         border: solid 1px black;
 }
 
 div.error {
         color: red;
         font-weight: bold;
         margin: 1em 2em;
 }
 
 a.ls-blob, a.ls-dir, a.ls-mod {
         font-family: monospace;
 }
 
 td.ls-size {
         text-align: right;
         font-family: monospace;
         width: 10em;
 }
 
 td.ls-mode {
         font-family: monospace;
         width: 10em;
 }
 
 table.blob {
         margin-top: 0.5em;
         border-top: solid 1px black;
 }
 
 table.blob td.lines {
         margin: 0; padding: 0 0 0 0.5em;
         vertical-align: top;
         color: black;
 }
 
 table.blob td.linenumbers {
         margin: 0; padding: 0 0.5em 0 0.5em;
         vertical-align: top;
         text-align: right;
         border-right: 1px solid gray;
 }
 
 table.blob pre {
         padding: 0; margin: 0;
 }
 
 table.blob a.no {
         color: gray;
         text-align: right;
         text-decoration: none;
 }
 
 table.blob a.no a:hover {
         color: black;
 }
 
 table.bin-blob {
         margin-top: 0.5em;
         border: solid 1px black;
 }
 
 table.bin-blob th {
         font-family: monospace;
         white-space: pre;
         border: solid 1px #777;
         padding: 0.5em 1em;
 }
 
 table.bin-blob td {
         font-family: monospace;
         white-space: pre;
         border-left: solid 1px #777;
         padding: 0em 1em;
 }
 
 table.nowrap td {
         white-space: nowrap;
 }
 
 table.commit-info {
         border-collapse: collapse;
         margin-top: 1.5em;
 }
 
 table.commit-info th {
         text-align: left;
         font-weight: normal;
         padding: 0.1em 1em 0.1em 0.1em;
         vertical-align: top;
 }
 
 table.commit-info td {
         font-weight: normal;
         padding: 0.1em 1em 0.1em 0.1em;
 }
 
 div.commit-subject {
         font-weight: bold;
         font-size: 125%;
         margin: 1.5em 0em 0.5em 0em;
         padding: 0em;
 }
 
 div.commit-msg {
         white-space: pre;
         font-family: monospace;
 }
 
 div.notes-header {
         font-weight: bold;
         padding-top: 1.5em;
 }
 
 div.notes {
         white-space: pre;
         font-family: monospace;
         border: solid 1px #ee9;
         background-color: #ffd;
         padding: 0.3em 2em 0.3em 1em;
         float: left;
 }
 
 div.notes-footer {
         clear: left;
 }
 
 div.diffstat-header {
@@ -542,193 +547,193 @@ a.remote-deco {
         background-color: #ccccff;
         border: solid 1px #000077;
 }
 a.deco {
         margin: 0px 0.5em;
         padding: 0px 0.25em;
         background-color: #ff8888;
         border: solid 1px #770000;
 }
 
 div.commit-subject a.branch-deco,
 div.commit-subject a.tag-deco,
 div.commit-subject a.remote-deco,
 div.commit-subject a.deco {
         margin-left: 1em;
         font-size: 75%;
 }
 
 table.stats {
         border: solid 1px black;
         border-collapse: collapse;
 }
 
 table.stats th {
         text-align: left;
         padding: 1px 0.5em;
         background-color: #eee;
         border: solid 1px black;
 }
 
 table.stats td {
         text-align: right;
         padding: 1px 0.5em;
         border: solid 1px black;
 }
 
 table.stats td.total {
         font-weight: bold;
         text-align: left;
 }
 
 table.stats td.sum {
         color: #c00;
         font-weight: bold;
         /*background-color: #eee; */
 }
 
 table.stats td.left {
         text-align: left;
 }
 
 table.vgraph {
         border-collapse: separate;
         border: solid 1px black;
         height: 200px;
 }
 
 table.vgraph th {
         background-color: #eee;
         font-weight: bold;
         border: solid 1px white;
         padding: 1px 0.5em;
 }
 
 table.vgraph td {
         vertical-align: bottom;
         padding: 0px 10px;
 }
 
 table.vgraph div.bar {
         background-color: #eee;
 }
 
 table.hgraph {
         border: solid 1px black;
         width: 800px;
 }
 
 table.hgraph th {
         background-color: #eee;
         font-weight: bold;
         border: solid 1px black;
         padding: 1px 0.5em;
 }
 
 table.hgraph td {
         vertical-align: center;
         padding: 2px 2px;
 }
 
 table.hgraph div.bar {
         background-color: #eee;
         height: 1em;
 }
 
 table.ssdiff {
         width: 100%;
 }
 
 table.ssdiff td {
         font-size: 75%;
         font-family: monospace;
         white-space: pre;
         padding: 1px 4px 1px 4px;
         border-left: solid 1px #aaa;
         border-right: solid 1px #aaa;
 }
 
 table.ssdiff td.add {
         color: black;
         background: #cfc;
         min-width: 50%;
 }
 
 table.ssdiff td.add_dark {
         color: black;
         background: #aca;
         min-width: 50%;
 }
 
 table.ssdiff span.add {
         background: #cfc;
         font-weight: bold;
 }
 
 table.ssdiff td.del {
         color: black;
         background: #fcc;
         min-width: 50%;
 }
 
 table.ssdiff td.del_dark {
         color: black;
         background: #caa;
         min-width: 50%;
 }
 
 table.ssdiff span.del {
         background: #fcc;
         font-weight: bold;
 }
 
 table.ssdiff td.changed {
         color: black;
         background: #ffc;
         min-width: 50%;
 }
 
 table.ssdiff td.changed_dark {
         color: black;
         background: #cca;
         min-width: 50%;
 }
 
 table.ssdiff td.lineno {
         color: black;
         background: #eee;
         text-align: right;
         width: 3em;
         min-width: 3em;
 }
 
 table.ssdiff td.hunk {
         color: #black;
         background: #ccf;
         border-top: solid 1px #aaa;
         border-bottom: solid 1px #aaa;
 }
 
 table.ssdiff td.head {
         border-top: solid 1px #aaa;
         border-bottom: solid 1px #aaa;
 }
 
 table.ssdiff td.head div.head {
         font-weight: bold;
         color: black;
 }
 
 table.ssdiff td.foot {
         border-top: solid 1px #aaa;
         border-left: none;
         border-right: none;
         border-bottom: none;
 }
 
 table.ssdiff td.space {
         border: none;
 }
 
 table.ssdiff td.space div {
         min-height: 3em;
-}
\ No newline at end of file
+}
diff --git a/cgit.h b/cgit.h
index f5f68ac..bed770b 100644
--- a/cgit.h
+++ b/cgit.h
@@ -1,318 +1,321 @@
 #ifndef CGIT_H
 #define CGIT_H
 
 
 #include <git-compat-util.h>
 #include <cache.h>
 #include <grep.h>
 #include <object.h>
 #include <tree.h>
 #include <commit.h>
 #include <tag.h>
 #include <diff.h>
 #include <diffcore.h>
 #include <refs.h>
 #include <revision.h>
 #include <log-tree.h>
 #include <archive.h>
 #include <string-list.h>
 #include <xdiff-interface.h>
 #include <xdiff/xdiff.h>
 #include <utf8.h>
 #include <notes.h>
+#include <graph.h>
 
 
 /*
  * Dateformats used on misc. pages
  */
 #define FMT_LONGDATE "%Y-%m-%d %H:%M:%S (%Z)"
 #define FMT_SHORTDATE "%Y-%m-%d"
 #define FMT_ATOMDATE "%Y-%m-%dT%H:%M:%SZ"
 
 
 /*
  * Limits used for relative dates
  */
 #define TM_MIN    60
 #define TM_HOUR  (TM_MIN * 60)
 #define TM_DAY   (TM_HOUR * 24)
 #define TM_WEEK  (TM_DAY * 7)
 #define TM_YEAR  (TM_DAY * 365)
 #define TM_MONTH (TM_YEAR / 12.0)
 
 
 /*
  * Default encoding
  */
 #define PAGE_ENCODING "UTF-8"
 
 typedef void (*configfn)(const char *name, const char *value);
 typedef void (*filepair_fn)(struct diff_filepair *pair);
 typedef void (*linediff_fn)(char *line, int len);
 
 struct cgit_filter {
         char *cmd;
         char **argv;
         int old_stdout;
         int pipe_fh[2];
         int pid;
         int exitstatus;
 };
 
 struct cgit_repo {
         char *url;
         char *name;
         char *path;
         char *desc;
         char *owner;
         char *defbranch;
         char *module_link;
         char *readme;
         char *section;
         char *clone_url;
         int snapshots;
+        int enable_commit_graph;
         int enable_log_filecount;
         int enable_log_linecount;
         int enable_remote_branches;
         int enable_subject_links;
         int max_stats;
         time_t mtime;
         struct cgit_filter *about_filter;
         struct cgit_filter *commit_filter;
         struct cgit_filter *source_filter;
 };
 
 typedef void (*repo_config_fn)(struct cgit_repo *repo, const char *name,
               const char *value);
 
 struct cgit_repolist {
         int length;
         int count;
         struct cgit_repo *repos;
 };
 
 struct commitinfo {
         struct commit *commit;
         char *author;
         char *author_email;
         unsigned long author_date;
         char *committer;
         char *committer_email;
         unsigned long committer_date;
         char *subject;
         char *msg;
         char *msg_encoding;
 };
 
 struct taginfo {
         char *tagger;
         char *tagger_email;
         unsigned long tagger_date;
         char *msg;
 };
 
 struct refinfo {
         const char *refname;
         struct object *object;
         union {
                 struct taginfo *tag;
                 struct commitinfo *commit;
         };
 };
 
 struct reflist {
         struct refinfo **refs;
         int alloc;
         int count;
 };
 
 struct cgit_query {
         int has_symref;
         int has_sha1;
         char *raw;
         char *repo;
         char *page;
         char *search;
         char *grep;
         char *head;
         char *sha1;
         char *sha2;
         char *path;
         char *name;
         char *mimetype;
         char *url;
         char *period;
         int   ofs;
         int nohead;
         char *sort;
         int showmsg;
         int ssdiff;
         int show_all;
         int context;
         int ignorews;
         char *vpath;
 };
 
 struct cgit_config {
         char *agefile;
         char *cache_root;
         char *clone_prefix;
         char *css;
         char *favicon;
         char *footer;
         char *head_include;
         char *header;
         char *index_header;
         char *index_info;
         char *logo;
         char *logo_link;
         char *module_link;
         char *project_list;
         char *readme;
         char *robots;
         char *root_title;
         char *root_desc;
         char *root_readme;
         char *script_name;
         char *section;
         char *virtual_root;
         char *strict_export;
         int cache_size;
         int cache_dynamic_ttl;
         int cache_max_create_time;
         int cache_repo_ttl;
         int cache_root_ttl;
         int cache_scanrc_ttl;
         int cache_static_ttl;
         int embedded;
         int enable_filter_overrides;
         int enable_gitweb_owner;
         int enable_index_links;
+        int enable_commit_graph;
         int enable_log_filecount;
         int enable_log_linecount;
         int enable_remote_branches;
         int enable_subject_links;
         int enable_tree_linenumbers;
         int local_time;
         int max_atom_items;
         int max_repo_count;
         int max_commit_count;
         int max_lock_attempts;
         int max_msg_len;
         int max_repodesc_len;
         int max_blob_size;
         int max_stats;
         int nocache;
         int noplainemail;
         int noheader;
         int renamelimit;
         int remove_suffix;
         int section_from_path;
         int snapshots;
         int summary_branches;
         int summary_log;
         int summary_tags;
         int ssdiff;
         struct string_list mimetypes;
         struct cgit_filter *about_filter;
         struct cgit_filter *commit_filter;
         struct cgit_filter *source_filter;
 };
 
 struct cgit_page {
         time_t modified;
         time_t expires;
         size_t size;
         char *mimetype;
         char *charset;
         char *filename;
         char *etag;
         char *title;
         int status;
         char *statusmsg;
 };
 
 struct cgit_environment {
         char *cgit_config;
         char *http_host;
         char *https;
         char *no_http;
         char *path_info;
         char *query_string;
         char *request_method;
         char *script_name;
         char *server_name;
         char *server_port;
 };
 
 struct cgit_context {
         struct cgit_environment env;
         struct cgit_query qry;
         struct cgit_config cfg;
         struct cgit_repo *repo;
         struct cgit_page page;
 };
 
 struct cgit_snapshot_format {
         const char *suffix;
         const char *mimetype;
         write_archive_fn_t write_func;
         int bit;
 };
 
 extern const char *cgit_version;
 
 extern struct cgit_repolist cgit_repolist;
 extern struct cgit_context ctx;
 extern const struct cgit_snapshot_format cgit_snapshot_formats[];
 
 extern struct cgit_repo *cgit_add_repo(const char *url);
 extern struct cgit_repo *cgit_get_repoinfo(const char *url);
 extern void cgit_repo_config_cb(const char *name, const char *value);
 
 extern int chk_zero(int result, char *msg);
 extern int chk_positive(int result, char *msg);
 extern int chk_non_negative(int result, char *msg);
 
 extern char *trim_end(const char *str, char c);
 extern char *strlpart(char *txt, int maxlen);
 extern char *strrpart(char *txt, int maxlen);
 
 extern void cgit_add_ref(struct reflist *list, struct refinfo *ref);
 extern int cgit_refs_cb(const char *refname, const unsigned char *sha1,
                         int flags, void *cb_data);
 
 extern void *cgit_free_commitinfo(struct commitinfo *info);
 
 extern int cgit_diff_files(const unsigned char *old_sha1,
                            const unsigned char *new_sha1,
                            unsigned long *old_size, unsigned long *new_size,
                            int *binary, int context, int ignorews,
                            linediff_fn fn);
 
 extern void cgit_diff_tree(const unsigned char *old_sha1,
                            const unsigned char *new_sha1,
                            filepair_fn fn, const char *prefix, int ignorews);
 
 extern void cgit_diff_commit(struct commit *commit, filepair_fn fn,
                              const char *prefix);
 
 __attribute__((format (printf,1,2)))
 extern char *fmt(const char *format,...);
 
 extern struct commitinfo *cgit_parse_commit(struct commit *commit);
 extern struct taginfo *cgit_parse_tag(struct tag *tag);
 extern void cgit_parse_url(const char *url);
 
 extern const char *cgit_repobasename(const char *reponame);
 
 extern int cgit_parse_snapshots_mask(const char *str);
 
 extern int cgit_open_filter(struct cgit_filter *filter);
 extern int cgit_close_filter(struct cgit_filter *filter);
 
 extern int readfile(const char *path, char **buf, size_t *size);
 
 extern char *expand_macros(const char *txt);
 
 #endif /* CGIT_H */
diff --git a/cgitrc.5.txt b/cgitrc.5.txt
index 75b6584..b45c46b 100644
--- a/cgitrc.5.txt
+++ b/cgitrc.5.txt
@@ -1,570 +1,583 @@
 :man source:   cgit
 :man manual:   cgit
 
 CGITRC(5)
 ========
 
 
 NAME
 ----
 cgitrc - runtime configuration for cgit
 
 
 SYNOPSIS
 --------
 Cgitrc contains all runtime settings for cgit, including the list of git
 repositories, formatted as a line-separated list of NAME=VALUE pairs. Blank
 lines, and lines starting with '#', are ignored.
 
 
 LOCATION
 --------
 The default location of cgitrc, defined at compile time, is /etc/cgitrc. At
 runtime, cgit will consult the environment variable CGIT_CONFIG and, if
 defined, use its value instead.
 
 
 GLOBAL SETTINGS
 ---------------
 about-filter::
         Specifies a command which will be invoked to format the content of
         about pages (both top-level and for each repository). The command will
         get the content of the about-file on its STDIN, and the STDOUT from the
         command will be included verbatim on the about page. Default value:
         none.
 
 agefile::
         Specifies a path, relative to each repository path, which can be used
         to specify the date and time of the youngest commit in the repository.
         The first line in the file is used as input to the "parse_date"
         function in libgit. Recommended timestamp-format is "yyyy-mm-dd
         hh:mm:ss". Default value: "info/web/last-modified".
 
 cache-root::
         Path used to store the cgit cache entries. Default value:
         "/var/cache/cgit".
 
 cache-dynamic-ttl::
         Number which specifies the time-to-live, in minutes, for the cached
         version of repository pages accessed without a fixed SHA1. Default
         value: "5".
 
 cache-repo-ttl::
         Number which specifies the time-to-live, in minutes, for the cached
         version of the repository summary page. Default value: "5".
 
 cache-root-ttl::
         Number which specifies the time-to-live, in minutes, for the cached
         version of the repository index page. Default value: "5".
 
 cache-scanrc-ttl::
         Number which specifies the time-to-live, in minutes, for the result
         of scanning a path for git repositories. Default value: "15".
 
 cache-size::
         The maximum number of entries in the cgit cache. Default value: "0"
         (i.e. caching is disabled).
 
 cache-static-ttl::
         Number which specifies the time-to-live, in minutes, for the cached
         version of repository pages accessed with a fixed SHA1. Default value:
         "5".
 
 clone-prefix::
         Space-separated list of common prefixes which, when combined with a
         repository url, generates valid clone urls for the repository. This
         setting is only used if `repo.clone-url` is unspecified. Default value:
         none.
 
 commit-filter::
         Specifies a command which will be invoked to format commit messages.
         The command will get the message on its STDIN, and the STDOUT from the
         command will be included verbatim as the commit message, i.e. this can
         be used to implement bugtracker integration. Default value: none.
 
 css::
         Url which specifies the css document to include in all cgit pages.
         Default value: "/cgit.css".
 
 embedded::
         Flag which, when set to "1", will make cgit generate a html fragment
         suitable for embedding in other html pages. Default value: none. See
         also: "noheader".
-        
+
+enable-commit-graph::
+        Flag which, when set to "1", will make cgit print an ASCII-art commit
+        history graph to the left of the commit messages in the repository
+        log page. Default value: "0".
+
 enable-filter-overrides::
         Flag which, when set to "1", allows all filter settings to be
         overridden in repository-specific cgitrc files. Default value: none.
 
 enable-gitweb-owner::
         If set to "1" and scan-path is enabled, we first check each repository
         for the git config value "gitweb.owner" to determine the owner.
         Default value: "1". See also: scan-path.
 
 enable-index-links::
         Flag which, when set to "1", will make cgit generate extra links for
         each repo in the repository index (specifically, to the "summary",
         "commit" and "tree" pages). Default value: "0".
 
 enable-log-filecount::
         Flag which, when set to "1", will make cgit print the number of
         modified files for each commit on the repository log page. Default
         value: "0".
 
 enable-log-linecount::
         Flag which, when set to "1", will make cgit print the number of added
         and removed lines for each commit on the repository log page. Default
         value: "0".
 
 enable-remote-branches::
         Flag which, when set to "1", will make cgit display remote branches
         in the summary and refs views. Default value: "0". See also:
         "repo.enable-remote-branches".
 
 enable-subject-links::
         Flag which, when set to "1", will make cgit use the subject of the
         parent commit as link text when generating links to parent commits
         in commit view. Default value: "0". See also:
         "repo.enable-subject-links".
 
 enable-tree-linenumbers::
         Flag which, when set to "1", will make cgit generate linenumber links
         for plaintext blobs printed in the tree view. Default value: "1".
 
 favicon::
         Url used as link to a shortcut icon for cgit. If specified, it is
         suggested to use the value "/favicon.ico" since certain browsers will
         ignore other values. Default value: none.
 
 footer::
         The content of the file specified with this option will be included
         verbatim at the bottom of all pages (i.e. it replaces the standard
         "generated by..." message. Default value: none.
 
 head-include::
         The content of the file specified with this option will be included
         verbatim in the html HEAD section on all pages. Default value: none.
 
 header::
         The content of the file specified with this option will be included
         verbatim at the top of all pages. Default value: none.
 
 include::
         Name of a configfile to include before the rest of the current config-
         file is parsed. Default value: none.
 
 index-header::
         The content of the file specified with this option will be included
         verbatim above the repository index. This setting is deprecated, and
         will not be supported by cgit-1.0 (use root-readme instead). Default
         value: none.
 
 index-info::
         The content of the file specified with this option will be included
         verbatim below the heading on the repository index page. This setting
         is deprecated, and will not be supported by cgit-1.0 (use root-desc
         instead). Default value: none.
 
 local-time::
         Flag which, if set to "1", makes cgit print commit and tag times in the
         servers timezone. Default value: "0".
 
 logo::
         Url which specifies the source of an image which will be used as a logo
         on all cgit pages. Default value: "/cgit.png".
 
 logo-link::
         Url loaded when clicking on the cgit logo image. If unspecified the
         calculated url of the repository index page will be used. Default
         value: none.
 
 max-atom-items::
         Specifies the number of items to display in atom feeds view. Default
         value: "10".
 
 max-commit-count::
         Specifies the number of entries to list per page in "log" view. Default
         value: "50".
 
 max-message-length::
         Specifies the maximum number of commit message characters to display in
         "log" view. Default value: "80".
 
 max-repo-count::
                 Specifies the number of entries to list per page on therepository
         index page. Default value: "50".
 
 max-repodesc-length::
         Specifies the maximum number of repo description characters to display
         on the repository index page. Default value: "80".
 
 max-blob-size::
         Specifies the maximum size of a blob to display HTML for in KBytes.
         Default value: "0" (limit disabled).
 
 max-stats::
         Set the default maximum statistics period. Valid values are "week",
         "month", "quarter" and "year". If unspecified, statistics are
         disabled. Default value: none. See also: "repo.max-stats".
 
 mimetype.<ext>::
         Set the mimetype for the specified filename extension. This is used
         by the `plain` command when returning blob content.
 
 module-link::
         Text which will be used as the formatstring for a hyperlink when a
         submodule is printed in a directory listing. The arguments for the
         formatstring are the path and SHA1 of the submodule commit. Default
         value: "./?repo=%s&page=commit&id=%s"
 
 nocache::
         If set to the value "1" caching will be disabled. This settings is
         deprecated, and will not be honored starting with cgit-1.0. Default
         value: "0".
 
 noplainemail::
         If set to "1" showing full author email adresses will be disabled.
         Default value: "0".
 
 noheader::
         Flag which, when set to "1", will make cgit omit the standard header
         on all pages. Default value: none. See also: "embedded".
 
 project-list::
         A list of subdirectories inside of scan-path, relative to it, that
         should loaded as git repositories. This must be defined prior to
         scan-path. Default value: none. See also: scan-path.
 
 readme::
         Text which will be used as default value for "repo.readme". Default
         value: none.
 
 remove-suffix::
         If set to "1" and scan-path is enabled, if any repositories are found
         with a suffix of ".git", this suffix will be removed for the url and
         name. Default value: "0". See also: scan-path.
 
 renamelimit::
         Maximum number of files to consider when detecting renames. The value
          "-1" uses the compiletime value in git (for further info, look at
           `man git-diff`). Default value: "-1".
 
 repo.group::
         Legacy alias for "section". This option is deprecated and will not be
         supported in cgit-1.0.
 
 robots::
         Text used as content for the "robots" meta-tag. Default value:
         "index, nofollow".
 
 root-desc::
         Text printed below the heading on the repository index page. Default
         value: "a fast webinterface for the git dscm".
 
 root-readme::
         The content of the file specified with this option will be included
         verbatim below the "about" link on the repository index page. Default
         value: none.
 
 root-title::
         Text printed as heading on the repository index page. Default value:
         "Git Repository Browser".
 
 scan-path::
         A path which will be scanned for repositories. If caching is enabled,
         the result will be cached as a cgitrc include-file in the cache
         directory. If project-list has been defined prior to scan-path,
         scan-path loads only the directories listed in the file pointed to by
         project-list. Default value: none. See also: cache-scanrc-ttl,
         project-list.
 
 section::
         The name of the current repository section - all repositories defined
         after this option will inherit the current section name. Default value:
         none.
 
 section-from-path::
         A number which, if specified before scan-path, specifies how many
         path elements from each repo path to use as a default section name.
         If negative, cgit will discard the specified number of path elements
         above the repo directory. Default value: 0.
 
 side-by-side-diffs::
         If set to "1" shows side-by-side diffs instead of unidiffs per
         default. Default value: "0".
 
 snapshots::
         Text which specifies the default set of snapshot formats generated by
         cgit. The value is a space-separated list of zero or more of the
         values "tar", "tar.gz", "tar.bz2" and "zip". Default value: none.
 
 source-filter::
         Specifies a command which will be invoked to format plaintext blobs
         in the tree view. The command will get the blob content on its STDIN
         and the name of the blob as its only command line argument. The STDOUT
         from the command will be included verbatim as the blob contents, i.e.
         this can be used to implement e.g. syntax highlighting. Default value:
         none.
 
 summary-branches::
         Specifies the number of branches to display in the repository "summary"
         view. Default value: "10".
 
 summary-log::
         Specifies the number of log entries to display in the repository
         "summary" view. Default value: "10".
 
 summary-tags::
         Specifies the number of tags to display in the repository "summary"
         view. Default value: "10".
 
 strict-export::
         Filename which, if specified, needs to be present within the repository
         for cgit to allow access to that repository. This can be used to emulate
         gitweb's EXPORT_OK and STRICT_EXPORT functionality and limit cgit's
         repositories to match those exported by git-daemon. This option MUST come
         before 'scan-path'.
 
 virtual-root::
         Url which, if specified, will be used as root for all cgit links. It
         will also cause cgit to generate 'virtual urls', i.e. urls like
         '/cgit/tree/README' as opposed to '?r=cgit&p=tree&path=README'. Default
         value: none.
         NOTE: cgit has recently learned how to use PATH_INFO to achieve the
         same kind of virtual urls, so this option will probably be deprecated.
 
 REPOSITORY SETTINGS
 -------------------
 repo.about-filter::
         Override the default about-filter. Default value: none. See also:
         "enable-filter-overrides".
 
 repo.clone-url::
         A list of space-separated urls which can be used to clone this repo.
         Default value: none.
 
 repo.commit-filter::
         Override the default commit-filter. Default value: none. See also:
         "enable-filter-overrides".
 
 repo.defbranch::
         The name of the default branch for this repository. If no such branch
         exists in the repository, the first branch name (when sorted) is used
         as default instead. Default value: "master".
 
 repo.desc::
         The value to show as repository description. Default value: none.
 
+repo.enable-commit-graph::
+        A flag which can be used to disable the global setting
+        `enable-commit-graph'. Default value: none.
+
 repo.enable-log-filecount::
         A flag which can be used to disable the global setting
         `enable-log-filecount'. Default value: none.
 
 repo.enable-log-linecount::
         A flag which can be used to disable the global setting
         `enable-log-linecount'. Default value: none.
 
 repo.enable-remote-branches::
         Flag which, when set to "1", will make cgit display remote branches
         in the summary and refs views. Default value: <enable-remote-branches>.
 
 repo.enable-subject-links::
         A flag which can be used to override the global setting
         `enable-subject-links'. Default value: none.
 
 repo.max-stats::
         Override the default maximum statistics period. Valid values are equal
         to the values specified for the global "max-stats" setting. Default
         value: none.
 
 repo.name::
         The value to show as repository name. Default value: <repo.url>.
 
 repo.owner::
         A value used to identify the owner of the repository. Default value:
         none.
 
 repo.path::
         An absolute path to the repository directory. For non-bare repositories
         this is the .git-directory. Default value: none.
 
 repo.readme::
         A path (relative to <repo.path>) which specifies a file to include
         verbatim as the "About" page for this repo. You may also specify a
         git refspec by head or by hash by prepending the refspec followed by
         a colon. For example, "master:docs/readme.mkd" Default value: <readme>.
 
 repo.snapshots::
         A mask of allowed snapshot-formats for this repo, restricted by the
         "snapshots" global setting. Default value: <snapshots>.
 
 repo.section::
         Override the current section name for this repository. Default value:
         none.
 
 repo.source-filter::
         Override the default source-filter. Default value: none. See also:
         "enable-filter-overrides".
 
 repo.url::
         The relative url used to access the repository. This must be the first
         setting specified for each repo. Default value: none.
 
 
 REPOSITORY-SPECIFIC CGITRC FILE
 -------------------------------
 When the option "scan-path" is used to auto-discover git repositories, cgit
 will try to parse the file "cgitrc" within any found repository. Such a
 repo-specific config file may contain any of the repo-specific options
 described above, except "repo.url" and "repo.path". Additionally, the "filter"
 options are only acknowledged in repo-specific config files when
 "enable-filter-overrides" is set to "1".
 
 Note: the "repo." prefix is dropped from the option names in repo-specific
 config files, e.g. "repo.desc" becomes "desc".
 
 
 EXAMPLE CGITRC FILE
 -------------------
 
 ....
 # Enable caching of up to 1000 output entriess
 cache-size=1000
 
 
 # Specify some default clone prefixes
 clone-prefix=git://foobar.com ssh://foobar.com/pub/git http://foobar.com/git
 
 # Specify the css url
 css=/css/cgit.css
 
 
 # Show extra links for each repository on the index page
 enable-index-links=1
 
 
+# Enable ASCII art commit history graph on the log pages
+enable-commit-graph=1
+
+
 # Show number of affected files per commit on the log pages
 enable-log-filecount=1
 
 
 # Show number of added/removed lines per commit on the log pages
 enable-log-linecount=1
 
 
 # Add a cgit favicon
 favicon=/favicon.ico
 
 
 # Use a custom logo
 logo=/img/mylogo.png
 
 
 # Enable statistics per week, month and quarter
 max-stats=quarter
 
 
 # Set the title and heading of the repository index page
 root-title=foobar.com git repositories
 
 
 # Set a subheading for the repository index page
 root-desc=tracking the foobar development
 
 
 # Include some more info about foobar.com on the index page
 root-readme=/var/www/htdocs/about.html
 
 
 # Allow download of tar.gz, tar.bz2 and zip-files
 snapshots=tar.gz tar.bz2 zip
 
 
 ##
 ## List of common mimetypes
 ##
 
 mimetype.gif=image/gif
 mimetype.html=text/html
 mimetype.jpg=image/jpeg
 mimetype.jpeg=image/jpeg
 mimetype.pdf=application/pdf
 mimetype.png=image/png
 mimetype.svg=image/svg+xml
 
 
 ##
 ## List of repositories.
 ## PS: Any repositories listed when section is unset will not be
 ##     displayed under a section heading
 ## PPS: This list could be kept in a different file (e.g. '/etc/cgitrepos')
 ##      and included like this:
 ##        include=/etc/cgitrepos
 ##
 
 
 repo.url=foo
 repo.path=/pub/git/foo.git
 repo.desc=the master foo repository
 repo.owner=fooman@foobar.com
 repo.readme=info/web/about.html
 
 
 repo.url=bar
 repo.path=/pub/git/bar.git
 repo.desc=the bars for your foo
 repo.owner=barman@foobar.com
 repo.readme=info/web/about.html
 
 
 # The next repositories will be displayed under the 'extras' heading
 section=extras
 
 
 repo.url=baz
 repo.path=/pub/git/baz.git
 repo.desc=a set of extensions for bar users
 
 repo.url=wiz
 repo.path=/pub/git/wiz.git
 repo.desc=the wizard of foo
 
 
 # Add some mirrored repositories
 section=mirrors
 
 
 repo.url=git
 repo.path=/pub/git/git.git
 repo.desc=the dscm
 
 
 repo.url=linux
 repo.path=/pub/git/linux.git
 repo.desc=the kernel
 
 # Disable adhoc downloads of this repo
 repo.snapshots=0
 
 # Disable line-counts for this repo
 repo.enable-log-linecount=0
 
 # Restrict the max statistics period for this repo
 repo.max-stats=month
 ....
 
 
 BUGS
 ----
 Comments currently cannot appear on the same line as a setting; the comment
 will be included as part of the value. E.g. this line:
 
         robots=index  # allow indexing
 
 will generate the following html element:
 
         <meta name='robots' content='index  # allow indexing'/>
 
 
 
 AUTHOR
 ------
 Lars Hjemli <hjemli@gmail.com>
 Jason A. Donenfeld <Jason@zx2c4.com>
diff --git a/shared.c b/shared.c
index 765cd27..7ec2e19 100644
--- a/shared.c
+++ b/shared.c
@@ -1,250 +1,251 @@
 /* shared.c: global vars + some callback functions
  *
  * Copyright (C) 2006 Lars Hjemli
  *
  * Licensed under GNU General Public License v2
  *   (see COPYING for full license text)
  */
 
 #include "cgit.h"
 
 struct cgit_repolist cgit_repolist;
 struct cgit_context ctx;
 
 int chk_zero(int result, char *msg)
 {
         if (result != 0)
                 die("%s: %s", msg, strerror(errno));
         return result;
 }
 
 int chk_positive(int result, char *msg)
 {
         if (result <= 0)
                 die("%s: %s", msg, strerror(errno));
         return result;
 }
 
 int chk_non_negative(int result, char *msg)
 {
             if (result < 0)
                     die("%s: %s",msg, strerror(errno));
         return result;
 }
 
 struct cgit_repo *cgit_add_repo(const char *url)
 {
         struct cgit_repo *ret;
 
         if (++cgit_repolist.count > cgit_repolist.length) {
                 if (cgit_repolist.length == 0)
                         cgit_repolist.length = 8;
                 else
                         cgit_repolist.length *= 2;
                 cgit_repolist.repos = xrealloc(cgit_repolist.repos,
                                                cgit_repolist.length *
                                                sizeof(struct cgit_repo));
         }
 
         ret = &cgit_repolist.repos[cgit_repolist.count-1];
         memset(ret, 0, sizeof(struct cgit_repo));
         ret->url = trim_end(url, '/');
         ret->name = ret->url;
         ret->path = NULL;
         ret->desc = "[no description]";
         ret->owner = NULL;
         ret->section = ctx.cfg.section;
         ret->defbranch = "master";
         ret->snapshots = ctx.cfg.snapshots;
+        ret->enable_commit_graph = ctx.cfg.enable_commit_graph;
         ret->enable_log_filecount = ctx.cfg.enable_log_filecount;
         ret->enable_log_linecount = ctx.cfg.enable_log_linecount;
         ret->enable_remote_branches = ctx.cfg.enable_remote_branches;
         ret->enable_subject_links = ctx.cfg.enable_subject_links;
         ret->max_stats = ctx.cfg.max_stats;
         ret->module_link = ctx.cfg.module_link;
         ret->readme = ctx.cfg.readme;
         ret->mtime = -1;
         ret->about_filter = ctx.cfg.about_filter;
         ret->commit_filter = ctx.cfg.commit_filter;
         ret->source_filter = ctx.cfg.source_filter;
         return ret;
 }
 
 struct cgit_repo *cgit_get_repoinfo(const char *url)
 {
         int i;
         struct cgit_repo *repo;
 
         for (i=0; i<cgit_repolist.count; i++) {
                 repo = &cgit_repolist.repos[i];
                 if (!strcmp(repo->url, url))
                         return repo;
         }
         return NULL;
 }
 
 void *cgit_free_commitinfo(struct commitinfo *info)
 {
         free(info->author);
         free(info->author_email);
         free(info->committer);
         free(info->committer_email);
         free(info->subject);
         free(info->msg);
         free(info->msg_encoding);
         free(info);
         return NULL;
 }
 
 char *trim_end(const char *str, char c)
 {
         int len;
         char *s, *t;
 
         if (str == NULL)
                 return NULL;
         t = (char *)str;
         len = strlen(t);
         while(len > 0 && t[len - 1] == c)
                 len--;
 
         if (len == 0)
                 return NULL;
 
         c = t[len];
         t[len] = '\0';
         s = xstrdup(t);
         t[len] = c;
         return s;
 }
 
 char *strlpart(char *txt, int maxlen)
 {
         char *result;
 
         if (!txt)
                 return txt;
 
         if (strlen(txt) <= maxlen)
                 return txt;
         result = xmalloc(maxlen + 1);
         memcpy(result, txt, maxlen - 3);
         result[maxlen-1] = result[maxlen-2] = result[maxlen-3] = '.';
         result[maxlen] = '\0';
         return result;
 }
 
 char *strrpart(char *txt, int maxlen)
 {
         char *result;
 
         if (!txt)
                 return txt;
 
         if (strlen(txt) <= maxlen)
                 return txt;
         result = xmalloc(maxlen + 1);
         memcpy(result + 3, txt + strlen(txt) - maxlen + 4, maxlen - 3);
         result[0] = result[1] = result[2] = '.';
         return result;
 }
 
 void cgit_add_ref(struct reflist *list, struct refinfo *ref)
 {
         size_t size;
 
         if (list->count >= list->alloc) {
                 list->alloc += (list->alloc ? list->alloc : 4);
                 size = list->alloc * sizeof(struct refinfo *);
                 list->refs = xrealloc(list->refs, size);
         }
         list->refs[list->count++] = ref;
 }
 
 struct refinfo *cgit_mk_refinfo(const char *refname, const unsigned char *sha1)
 {
         struct refinfo *ref;
 
         ref = xmalloc(sizeof (struct refinfo));
         ref->refname = xstrdup(refname);
         ref->object = parse_object(sha1);
         switch (ref->object->type) {
         case OBJ_TAG:
                 ref->tag = cgit_parse_tag((struct tag *)ref->object);
                 break;
         case OBJ_COMMIT:
                 ref->commit = cgit_parse_commit((struct commit *)ref->object);
                 break;
         }
         return ref;
 }
 
 int cgit_refs_cb(const char *refname, const unsigned char *sha1, int flags,
                   void *cb_data)
 {
         struct reflist *list = (struct reflist *)cb_data;
         struct refinfo *info = cgit_mk_refinfo(refname, sha1);
 
         if (info)
                 cgit_add_ref(list, info);
         return 0;
 }
 
 void cgit_diff_tree_cb(struct diff_queue_struct *q,
                        struct diff_options *options, void *data)
 {
         int i;
 
         for (i = 0; i < q->nr; i++) {
                 if (q->queue[i]->status == 'U')
                         continue;
                 ((filepair_fn)data)(q->queue[i]);
         }
 }
 
 static int load_mmfile(mmfile_t *file, const unsigned char *sha1)
 {
         enum object_type type;
 
         if (is_null_sha1(sha1)) {
                 file->ptr = (char *)"";
                 file->size = 0;
         } else {
                 file->ptr = read_sha1_file(sha1, &type, 
                                            (unsigned long *)&file->size);
         }
         return 1;
 }
 
 /*
  * Receive diff-buffers from xdiff and concatenate them as
  * needed across multiple callbacks.
  *
  * This is basically a copy of xdiff-interface.c/xdiff_outf(),
  * ripped from git and modified to use globals instead of
  * a special callback-struct.
  */
 char *diffbuf = NULL;
 int buflen = 0;
 
 int filediff_cb(void *priv, mmbuffer_t *mb, int nbuf)
 {
         int i;
 
         for (i = 0; i < nbuf; i++) {
                 if (mb[i].ptr[mb[i].size-1] != '\n') {
                         /* Incomplete line */
                         diffbuf = xrealloc(diffbuf, buflen + mb[i].size);
                         memcpy(diffbuf + buflen, mb[i].ptr, mb[i].size);
                         buflen += mb[i].size;
                         continue;
                 }
 
                 /* we have a complete line */
                 if (!diffbuf) {
                         ((linediff_fn)priv)(mb[i].ptr, mb[i].size);
                         continue;
                 }
                 diffbuf = xrealloc(diffbuf, buflen + mb[i].size);
                 memcpy(diffbuf + buflen, mb[i].ptr, mb[i].size);
                 ((linediff_fn)priv)(diffbuf, buflen + mb[i].size);
diff --git a/ui-log.c b/ui-log.c
index 6d7fcae..0d86fd5 100644
--- a/ui-log.c
+++ b/ui-log.c
@@ -1,305 +1,366 @@
 /* ui-log.c: functions for log output
  *
  * Copyright (C) 2006 Lars Hjemli
  *
  * Licensed under GNU General Public License v2
  *   (see COPYING for full license text)
  */
 
 #include "cgit.h"
 #include "html.h"
 #include "ui-shared.h"
 #include "vector.h"
 
 int files, add_lines, rem_lines;
 
 void count_lines(char *line, int size)
 {
         if (size <= 0)
                 return;
 
         if (line[0] == '+')
                 add_lines++;
 
         else if (line[0] == '-')
                 rem_lines++;
 }
 
 void inspect_files(struct diff_filepair *pair)
 {
         unsigned long old_size = 0;
         unsigned long new_size = 0;
         int binary = 0;
 
         files++;
         if (ctx.repo->enable_log_linecount)
                 cgit_diff_files(pair->one->sha1, pair->two->sha1, &old_size,
                                 &new_size, &binary, 0, ctx.qry.ignorews,
                                 count_lines);
 }
 
 void show_commit_decorations(struct commit *commit)
 {
         struct name_decoration *deco;
         static char buf[1024];
 
         buf[sizeof(buf) - 1] = 0;
         deco = lookup_decoration(&name_decoration, &commit->object);
         while (deco) {
                 if (!prefixcmp(deco->name, "refs/heads/")) {
                         strncpy(buf, deco->name + 11, sizeof(buf) - 1);
                         cgit_log_link(buf, NULL, "branch-deco", buf, NULL,
                                       ctx.qry.vpath, 0, NULL, NULL,
                                       ctx.qry.showmsg);
                 }
                 else if (!prefixcmp(deco->name, "tag: refs/tags/")) {
                         strncpy(buf, deco->name + 15, sizeof(buf) - 1);
                         cgit_tag_link(buf, NULL, "tag-deco", ctx.qry.head, buf);
                 }
                 else if (!prefixcmp(deco->name, "refs/tags/")) {
                         strncpy(buf, deco->name + 10, sizeof(buf) - 1);
                         cgit_tag_link(buf, NULL, "tag-deco", ctx.qry.head, buf);
                 }
                 else if (!prefixcmp(deco->name, "refs/remotes/")) {
                         strncpy(buf, deco->name + 13, sizeof(buf) - 1);
                         cgit_log_link(buf, NULL, "remote-deco", NULL,
                                       sha1_to_hex(commit->object.sha1),
                                       ctx.qry.vpath, 0, NULL, NULL,
                                       ctx.qry.showmsg);
                 }
                 else {
                         strncpy(buf, deco->name, sizeof(buf) - 1);
                         cgit_commit_link(buf, NULL, "deco", ctx.qry.head,
                                          sha1_to_hex(commit->object.sha1),
                                          ctx.qry.vpath, 0);
                 }
                 deco = deco->next;
         }
 }
 
-void print_commit(struct commit *commit)
+void print_commit(struct commit *commit, struct rev_info *revs)
 {
         struct commitinfo *info;
         char *tmp;
         int cols = 2;
+        struct strbuf graphbuf = STRBUF_INIT;
+
+        if (ctx.repo->enable_log_filecount) {
+                cols++;
+                if (ctx.repo->enable_log_linecount)
+                        cols++;
+        }
+
+        if (revs->graph) {
+                /* Advance graph until current commit */
+                while (!graph_next_line(revs->graph, &graphbuf)) {
+                        /* Print graph segment in otherwise empty table row */
+                        html("<tr class='nohover'><td/><td class='commitgraph'>");
+                        html(graphbuf.buf);
+                        htmlf("</td><td colspan='%d' /></tr>\n", cols);
+                        strbuf_setlen(&graphbuf, 0);
+                }
+                /* Current commit's graph segment is now ready in graphbuf */
+        }
 
         info = cgit_parse_commit(commit);
         htmlf("<tr%s><td>",
                 ctx.qry.showmsg ? " class='logheader'" : "");
         tmp = fmt("id=%s", sha1_to_hex(commit->object.sha1));
         tmp = cgit_fileurl(ctx.repo->url, "commit", ctx.qry.vpath, tmp);
         html_link_open(tmp, NULL, NULL);
         cgit_print_age(commit->date, TM_WEEK * 2, FMT_SHORTDATE);
         html_link_close();
-        htmlf("</td><td%s>",
-                ctx.qry.showmsg ? " class='logsubject'" : "");
+        html("</td>");
+
+        if (revs->graph) {
+                /* Print graph segment for current commit */
+                html("<td class='commitgraph'>");
+                html(graphbuf.buf);
+                html("</td>");
+                strbuf_setlen(&graphbuf, 0);
+        }
+
+        htmlf("<td%s>", ctx.qry.showmsg ? " class='logsubject'" : "");
         cgit_commit_link(info->subject, NULL, NULL, ctx.qry.head,
                          sha1_to_hex(commit->object.sha1), ctx.qry.vpath, 0);
         show_commit_decorations(commit);
         html("</td><td>");
         html_txt(info->author);
         if (ctx.repo->enable_log_filecount) {
                 files = 0;
                 add_lines = 0;
                 rem_lines = 0;
                 cgit_diff_commit(commit, inspect_files, ctx.qry.vpath);
                 html("</td><td>");
                 htmlf("%d", files);
                 if (ctx.repo->enable_log_linecount) {
                         html("</td><td>");
                         htmlf("-%d/+%d", rem_lines, add_lines);
                 }
         }
         html("</td></tr>\n");
 
-        if (ctx.qry.showmsg) { /* Print message + notes in a second table row */
-                /* Concatenate commit message and notes in msgbuf */
+        if (revs->graph || ctx.qry.showmsg) { /* Print a second table row */
                 struct strbuf msgbuf = STRBUF_INIT;
-                if (info->msg && *(info->msg)) {
-                        strbuf_addstr(&msgbuf, info->msg);
+                html("<tr class='nohover'><td/>"); /* Empty 'Age' column */
+
+                if (ctx.qry.showmsg) {
+                        /* Concatenate commit message + notes in msgbuf */
+                        if (info->msg && *(info->msg)) {
+                                strbuf_addstr(&msgbuf, info->msg);
+                                strbuf_addch(&msgbuf, '\n');
+                        }
+                        format_note(NULL, commit->object.sha1, &msgbuf,
+                                    PAGE_ENCODING,
+                                    NOTES_SHOW_HEADER | NOTES_INDENT);
                         strbuf_addch(&msgbuf, '\n');
+                        strbuf_ltrim(&msgbuf);
                 }
-                format_note(NULL, commit->object.sha1, &msgbuf, PAGE_ENCODING,
-                            NOTES_SHOW_HEADER | NOTES_INDENT);
-                strbuf_addch(&msgbuf, '\n');
-                strbuf_ltrim(&msgbuf);
 
-                if (ctx.repo->enable_log_filecount) {
-                        cols++;
-                        if (ctx.repo->enable_log_linecount)
-                                cols++;
+                if (revs->graph) {
+                        int lines = 0;
+
+                        /* Calculate graph padding */
+                        if (ctx.qry.showmsg) {
+                                /* Count #lines in commit message + notes */
+                                const char *p = msgbuf.buf;
+                                lines = 1;
+                                while ((p = strchr(p, '\n'))) {
+                                        p++;
+                                        lines++;
+                                }
+                        }
+
+                        /* Print graph padding */
+                        html("<td class='commitgraph'>");
+                        while (lines > 0 || !graph_is_commit_finished(revs->graph)) {
+                                if (graphbuf.len)
+                                        html("\n");
+                                strbuf_setlen(&graphbuf, 0);
+                                graph_next_line(revs->graph, &graphbuf);
+                                html(graphbuf.buf);
+                                lines--;
+                        }
+                        html("</td>\n");
                 }
 
-                /* Create second table row containing msgbuf */
-                htmlf("<tr class='nohover'><td/><td colspan='%d' class='logmsg'>",
-                        cols);
+                /* Print msgbuf into remainder of table row */
+                htmlf("<td colspan='%d'%s>\n", cols,
+                        ctx.qry.showmsg ? " class='logmsg'" : "");
                 html_txt(msgbuf.buf);
                 html("</td></tr>\n");
                 strbuf_release(&msgbuf);
         }
 
+        strbuf_release(&graphbuf);
         cgit_free_commitinfo(info);
 }
 
 static const char *disambiguate_ref(const char *ref)
 {
         unsigned char sha1[20];
         const char *longref;
 
         longref = fmt("refs/heads/%s", ref);
         if (get_sha1(longref, sha1) == 0)
                 return longref;
 
         return ref;
 }
 
 static char *next_token(char **src)
 {
         char *result;
 
         if (!src || !*src)
                 return NULL;
         while (isspace(**src))
                 (*src)++;
         if (!**src)
                 return NULL;
         result = *src;
         while (**src) {
                 if (isspace(**src)) {
                         **src = '\0';
                         (*src)++;
                         break;
                 }
                 (*src)++;
         }
         return result;
 }
 
 void cgit_print_log(const char *tip, int ofs, int cnt, char *grep, char *pattern,
                     char *path, int pager)
 {
         struct rev_info rev;
         struct commit *commit;
         struct vector vec = VECTOR_INIT(char *);
         int i, columns = 3;
         char *arg;
 
         /* First argv is NULL */
         vector_push(&vec, NULL, 0);
 
         if (!tip)
                 tip = ctx.qry.head;
         tip = disambiguate_ref(tip);
         vector_push(&vec, &tip, 0);
 
         if (grep && pattern && *pattern) {
                 pattern = xstrdup(pattern);
                 if (!strcmp(grep, "grep") || !strcmp(grep, "author") ||
                     !strcmp(grep, "committer")) {
                         arg = fmt("--%s=%s", grep, pattern);
                         vector_push(&vec, &arg, 0);
                 }
                 if (!strcmp(grep, "range")) {
                         /* Split the pattern at whitespace and add each token
                          * as a revision expression. Do not accept other
                          * rev-list options. Also, replace the previously
                          * pushed tip (it's no longer relevant).
                          */
                         vec.count--;
                         while ((arg = next_token(&pattern))) {
                                 if (*arg == '-') {
                                         fprintf(stderr, "Bad range expr: %s\n",
                                                 arg);
                                         break;
                                 }
                                 vector_push(&vec, &arg, 0);
                         }
                 }
         }
+        if (ctx.repo->enable_commit_graph) {
+                static const char *graph_arg = "--graph";
+                vector_push(&vec, &graph_arg, 0);
+        }
 
         if (path) {
                 arg = "--";
                 vector_push(&vec, &arg, 0);
                 vector_push(&vec, &path, 0);
         }
 
         /* Make sure the vector is NULL-terminated */
         vector_push(&vec, NULL, 0);
         vec.count--;
 
         init_revisions(&rev, NULL);
         rev.abbrev = DEFAULT_ABBREV;
         rev.commit_format = CMIT_FMT_DEFAULT;
         rev.verbose_header = 1;
         rev.show_root_diff = 0;
         setup_revisions(vec.count, vec.data, &rev, NULL);
         load_ref_decorations(DECORATE_FULL_REFS);
         rev.show_decorations = 1;
         rev.grep_filter.regflags |= REG_ICASE;
         compile_grep_patterns(&rev.grep_filter);
         prepare_revision_walk(&rev);
 
         if (pager)
                 html("<table class='list nowrap'>");
 
-        html("<tr class='nohover'><th class='left'>Age</th>"
-              "<th class='left'>Commit message");
+        html("<tr class='nohover'><th class='left'>Age</th>");
+        if (ctx.repo->enable_commit_graph)
+                html("<th></th>");
+        html("<th class='left'>Commit message");
         if (pager) {
                 html(" (");
                 cgit_log_link(ctx.qry.showmsg ? "Collapse" : "Expand", NULL,
                               NULL, ctx.qry.head, ctx.qry.sha1,
                               ctx.qry.vpath, ctx.qry.ofs, ctx.qry.grep,
                               ctx.qry.search, ctx.qry.showmsg ? 0 : 1);
                 html(")");
         }
         html("</th><th class='left'>Author</th>");
         if (ctx.repo->enable_log_filecount) {
                 html("<th class='left'>Files</th>");
                 columns++;
                 if (ctx.repo->enable_log_linecount) {
                         html("<th class='left'>Lines</th>");
                         columns++;
                 }
         }
         html("</tr>\n");
 
         if (ofs<0)
                 ofs = 0;
 
         for (i = 0; i < ofs && (commit = get_revision(&rev)) != NULL; i++) {
                 free(commit->buffer);
                 commit->buffer = NULL;
                 free_commit_list(commit->parents);
                 commit->parents = NULL;
         }
 
         for (i = 0; i < cnt && (commit = get_revision(&rev)) != NULL; i++) {
-                print_commit(commit);
+                print_commit(commit, &rev);
                 free(commit->buffer);
                 commit->buffer = NULL;
                 free_commit_list(commit->parents);
                 commit->parents = NULL;
         }
         if (pager) {
                 html("</table><div class='pager'>");
                 if (ofs > 0) {
                         cgit_log_link("[prev]", NULL, NULL, ctx.qry.head,
                                       ctx.qry.sha1, ctx.qry.vpath,
                                       ofs - cnt, ctx.qry.grep,
                                       ctx.qry.search, ctx.qry.showmsg);
                         html("&nbsp;");
                 }
                 if ((commit = get_revision(&rev)) != NULL) {
                         cgit_log_link("[next]", NULL, NULL, ctx.qry.head,
                                       ctx.qry.sha1, ctx.qry.vpath,
                                       ofs + cnt, ctx.qry.grep,
                                       ctx.qry.search, ctx.qry.showmsg);
                 }
                 html("</div>");
         } else if ((commit = get_revision(&rev)) != NULL) {
                 html("<tr class='nohover'><td colspan='3'>");
                 cgit_log_link("[...]", NULL, NULL, ctx.qry.head, NULL,
                               ctx.qry.vpath, 0, NULL, NULL, ctx.qry.showmsg);
                 html("</td></tr>\n");
         }
 }