Add functions and types for ref lists

This adds two structs, refinfo and reflist, and functions for building
a list of refs.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>

2 files changed, 60 insertions, 0 deletions

diff --git a/cgit.h b/cgit.h
index e96311f..75e919b 100644
--- a/cgit.h
+++ b/cgit.h
@@ -1,249 +1,268 @@
 #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 <xdiff/xdiff.h>
 
 
 /*
  * The valid cgit repo-commands
  */
 #define CMD_LOG      1
 #define CMD_COMMIT   2
 #define CMD_DIFF     3
 #define CMD_TREE     4
 #define CMD_BLOB     5
 #define CMD_SNAPSHOT 6
 #define CMD_TAG      7
 
 /*
  * Dateformats used on misc. pages
  */
 #define FMT_LONGDATE "%Y-%m-%d %H:%M:%S"
 #define FMT_SHORTDATE "%Y-%m-%d"
 
 
 /*
  * 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)
 
 
 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 cacheitem {
         char *name;
         struct stat st;
         int ttl;
         int fd;
 };
 
 struct repoinfo {
         char *url;
         char *name;
         char *path;
         char *desc;
         char *owner;
         char *defbranch;
         char *group;
         char *module_link;
         char *readme;
         int snapshots;
         int enable_log_filecount;
         int enable_log_linecount;
 };
 
 struct repolist {
         int length;
         int count;
         struct repoinfo *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;
 };
 
 struct taginfo {
         char *tagger;
         char *tagger_email;
         int 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;
+};
+
 extern const char *cgit_version;
 
 extern struct repolist cgit_repolist;
 extern struct repoinfo *cgit_repo;
 extern int cgit_cmd;
 
 extern char *cgit_root_title;
 extern char *cgit_css;
 extern char *cgit_logo;
 extern char *cgit_index_header;
 extern char *cgit_logo_link;
 extern char *cgit_module_link;
 extern char *cgit_agefile;
 extern char *cgit_virtual_root;
 extern char *cgit_script_name;
 extern char *cgit_cache_root;
 extern char *cgit_repo_group;
 
 extern int cgit_nocache;
 extern int cgit_snapshots;
 extern int cgit_enable_index_links;
 extern int cgit_enable_log_filecount;
 extern int cgit_enable_log_linecount;
 extern int cgit_max_lock_attempts;
 extern int cgit_cache_root_ttl;
 extern int cgit_cache_repo_ttl;
 extern int cgit_cache_dynamic_ttl;
 extern int cgit_cache_static_ttl;
 extern int cgit_cache_max_create_time;
 extern int cgit_summary_log;
 
 extern int cgit_max_msg_len;
 extern int cgit_max_repodesc_len;
 extern int cgit_max_commit_count;
 
 extern int cgit_query_has_symref;
 extern int cgit_query_has_sha1;
 
 extern char *cgit_querystring;
 extern char *cgit_query_repo;
 extern char *cgit_query_page;
 extern char *cgit_query_search;
 extern char *cgit_query_head;
 extern char *cgit_query_sha1;
 extern char *cgit_query_sha2;
 extern char *cgit_query_path;
 extern char *cgit_query_name;
 extern int   cgit_query_ofs;
 
 extern int htmlfd;
 
 extern int cgit_get_cmd_index(const char *cmd);
 extern struct repoinfo *cgit_get_repoinfo(const char *url);
 extern void cgit_global_config_cb(const char *name, const char *value);
 extern void cgit_repo_config_cb(const char *name, const char *value);
 extern void cgit_querystring_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 int hextoint(char c);
 extern char *trim_end(const char *str, char c);
 
+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,
                            linediff_fn fn);
 
 extern void cgit_diff_tree(const unsigned char *old_sha1,
                            const unsigned char *new_sha1,
                            filepair_fn fn, const char *prefix);
 
 extern void cgit_diff_commit(struct commit *commit, filepair_fn fn);
 
 extern char *fmt(const char *format,...);
 
 extern void html(const char *txt);
 extern void htmlf(const char *format,...);
 extern void html_txt(char *txt);
 extern void html_ntxt(int len, char *txt);
 extern void html_attr(char *txt);
 extern void html_hidden(char *name, char *value);
 extern void html_link_open(char *url, char *title, char *class);
 extern void html_link_close(void);
 extern void html_filemode(unsigned short mode);
 extern int html_include(const char *filename);
 
 extern int cgit_read_config(const char *filename, configfn fn);
 extern int cgit_parse_query(char *txt, configfn fn);
 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 char *cache_safe_filename(const char *unsafe);
 extern int cache_lock(struct cacheitem *item);
 extern int cache_unlock(struct cacheitem *item);
 extern int cache_cancel_lock(struct cacheitem *item);
 extern int cache_exist(struct cacheitem *item);
 extern int cache_expired(struct cacheitem *item);
 
 extern char *cgit_repourl(const char *reponame);
 extern char *cgit_fileurl(const char *reponame, const char *pagename,
                           const char *filename, const char *query);
 extern char *cgit_pageurl(const char *reponame, const char *pagename,
                           const char *query);
 
 extern const char *cgit_repobasename(const char *reponame);
 
 extern void cgit_tree_link(char *name, char *title, char *class, char *head,
                            char *rev, char *path);
 extern void cgit_log_link(char *name, char *title, char *class, char *head,
                           char *rev, char *path, int ofs);
 extern void cgit_commit_link(char *name, char *title, char *class, char *head,
                              char *rev);
 extern void cgit_snapshot_link(char *name, char *title, char *class,
                                char *head, char *rev, char *archivename);
 extern void cgit_diff_link(char *name, char *title, char *class, char *head,
                            char *new_rev, char *old_rev, char *path);
 
 extern void cgit_object_link(struct object *obj);
 
 extern void cgit_print_error(char *msg);
 extern void cgit_print_date(time_t secs, char *format);
 extern void cgit_print_age(time_t t, time_t max_relative, char *format);
 extern void cgit_print_docstart(char *title, struct cacheitem *item);
 extern void cgit_print_docend();
 extern void cgit_print_pageheader(char *title, int show_search);
 extern void cgit_print_snapshot_start(const char *mimetype,
                                       const char *filename,
                                       struct cacheitem *item);
 
 extern void cgit_print_repolist(struct cacheitem *item);
 extern void cgit_print_summary();
 extern void cgit_print_log(const char *tip, int ofs, int cnt, char *grep, char *path, int pager);
 extern void cgit_print_blob(struct cacheitem *item, const char *hex, char *path);
 extern void cgit_print_tree(const char *rev, char *path);
 extern void cgit_print_commit(char *hex);
 extern void cgit_print_tag(char *revname);
 extern void cgit_print_diff(const char *new_hex, const char *old_hex, const char *prefix);
 extern void cgit_print_snapshot(struct cacheitem *item, const char *head,
                                 const char *hex, const char *prefix,
                                 const char *filename, int snapshot);
 extern void cgit_print_snapshot_links(const char *repo, const char *head,
                                       const char *hex, int snapshots);
 extern int cgit_parse_snapshots_mask(const char *str);
 
 #endif /* CGIT_H */
diff --git a/shared.c b/shared.c
index 3d4feea..d815cb1 100644
--- a/shared.c
+++ b/shared.c
@@ -1,425 +1,466 @@
 /* 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 repolist cgit_repolist;
 struct repoinfo *cgit_repo;
 int cgit_cmd;
 
 const char *cgit_version = CGIT_VERSION;
 
 char *cgit_root_title   = "Git repository browser";
 char *cgit_css          = "/cgit.css";
 char *cgit_logo         = "/git-logo.png";
 char *cgit_index_header = NULL;
 char *cgit_logo_link    = "http://www.kernel.org/pub/software/scm/git/docs/";
 char *cgit_module_link  = "./?repo=%s&page=commit&id=%s";
 char *cgit_agefile      = "info/web/last-modified";
 char *cgit_virtual_root = NULL;
 char *cgit_script_name  = CGIT_SCRIPT_NAME;
 char *cgit_cache_root   = CGIT_CACHE_ROOT;
 char *cgit_repo_group   = NULL;
 
 int cgit_nocache               =  0;
 int cgit_snapshots             =  0;
 int cgit_enable_index_links    =  0;
 int cgit_enable_log_filecount  =  0;
 int cgit_enable_log_linecount  =  0;
 int cgit_max_lock_attempts     =  5;
 int cgit_cache_root_ttl        =  5;
 int cgit_cache_repo_ttl        =  5;
 int cgit_cache_dynamic_ttl     =  5;
 int cgit_cache_static_ttl      = -1;
 int cgit_cache_max_create_time =  5;
 int cgit_summary_log           =  0;
 int cgit_renamelimit           = -1;
 
 int cgit_max_msg_len = 60;
 int cgit_max_repodesc_len = 60;
 int cgit_max_commit_count = 50;
 
 int cgit_query_has_symref = 0;
 int cgit_query_has_sha1   = 0;
 
 char *cgit_querystring  = NULL;
 char *cgit_query_repo   = NULL;
 char *cgit_query_page   = NULL;
 char *cgit_query_head   = NULL;
 char *cgit_query_search = NULL;
 char *cgit_query_sha1   = NULL;
 char *cgit_query_sha2   = NULL;
 char *cgit_query_path   = NULL;
 char *cgit_query_name   = NULL;
 int   cgit_query_ofs    = 0;
 
 int htmlfd = 0;
 
 
 int cgit_get_cmd_index(const char *cmd)
 {
         static char *cmds[] = {"log", "commit", "diff", "tree", "blob",
                                "snapshot", "tag", NULL};
         int i;
 
         for(i = 0; cmds[i]; i++)
                 if (!strcmp(cmd, cmds[i]))
                         return i + 1;
         return 0;
 }
 
 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 repoinfo *add_repo(const char *url)
 {
         struct repoinfo *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 repoinfo));
         }
 
         ret = &cgit_repolist.repos[cgit_repolist.count-1];
         ret->url = trim_end(url, '/');
         ret->name = ret->url;
         ret->path = NULL;
         ret->desc = NULL;
         ret->owner = NULL;
         ret->group = cgit_repo_group;
         ret->defbranch = "master";
         ret->snapshots = cgit_snapshots;
         ret->enable_log_filecount = cgit_enable_log_filecount;
         ret->enable_log_linecount = cgit_enable_log_linecount;
         ret->module_link = cgit_module_link;
         ret->readme = NULL;
         return ret;
 }
 
 struct repoinfo *cgit_get_repoinfo(const char *url)
 {
         int i;
         struct repoinfo *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_global_config_cb(const char *name, const char *value)
 {
         if (!strcmp(name, "root-title"))
                 cgit_root_title = xstrdup(value);
         else if (!strcmp(name, "css"))
                 cgit_css = xstrdup(value);
         else if (!strcmp(name, "logo"))
                 cgit_logo = xstrdup(value);
         else if (!strcmp(name, "index-header"))
                 cgit_index_header = xstrdup(value);
         else if (!strcmp(name, "logo-link"))
                 cgit_logo_link = xstrdup(value);
         else if (!strcmp(name, "module-link"))
                 cgit_module_link = xstrdup(value);
         else if (!strcmp(name, "virtual-root"))
                 cgit_virtual_root = trim_end(value, '/');
         else if (!strcmp(name, "nocache"))
                 cgit_nocache = atoi(value);
         else if (!strcmp(name, "snapshots"))
                 cgit_snapshots = cgit_parse_snapshots_mask(value);
         else if (!strcmp(name, "enable-index-links"))
                 cgit_enable_index_links = atoi(value);
         else if (!strcmp(name, "enable-log-filecount"))
                 cgit_enable_log_filecount = atoi(value);
         else if (!strcmp(name, "enable-log-linecount"))
                 cgit_enable_log_linecount = atoi(value);
         else if (!strcmp(name, "cache-root"))
                 cgit_cache_root = xstrdup(value);
         else if (!strcmp(name, "cache-root-ttl"))
                 cgit_cache_root_ttl = atoi(value);
         else if (!strcmp(name, "cache-repo-ttl"))
                 cgit_cache_repo_ttl = atoi(value);
         else if (!strcmp(name, "cache-static-ttl"))
                 cgit_cache_static_ttl = atoi(value);
         else if (!strcmp(name, "cache-dynamic-ttl"))
                 cgit_cache_dynamic_ttl = atoi(value);
         else if (!strcmp(name, "max-message-length"))
                 cgit_max_msg_len = atoi(value);
         else if (!strcmp(name, "max-repodesc-length"))
                 cgit_max_repodesc_len = atoi(value);
         else if (!strcmp(name, "max-commit-count"))
                 cgit_max_commit_count = atoi(value);
         else if (!strcmp(name, "summary-log"))
                 cgit_summary_log = atoi(value);
         else if (!strcmp(name, "agefile"))
                 cgit_agefile = xstrdup(value);
         else if (!strcmp(name, "renamelimit"))
                 cgit_renamelimit = atoi(value);
         else if (!strcmp(name, "repo.group"))
                 cgit_repo_group = xstrdup(value);
         else if (!strcmp(name, "repo.url"))
                 cgit_repo = add_repo(value);
         else if (!strcmp(name, "repo.name"))
                 cgit_repo->name = xstrdup(value);
         else if (cgit_repo && !strcmp(name, "repo.path"))
                 cgit_repo->path = trim_end(value, '/');
         else if (cgit_repo && !strcmp(name, "repo.desc"))
                 cgit_repo->desc = xstrdup(value);
         else if (cgit_repo && !strcmp(name, "repo.owner"))
                 cgit_repo->owner = xstrdup(value);
         else if (cgit_repo && !strcmp(name, "repo.defbranch"))
                 cgit_repo->defbranch = xstrdup(value);
         else if (cgit_repo && !strcmp(name, "repo.snapshots"))
                 cgit_repo->snapshots = cgit_snapshots & cgit_parse_snapshots_mask(value); /* XXX: &? */
         else if (cgit_repo && !strcmp(name, "repo.enable-log-filecount"))
                 cgit_repo->enable_log_filecount = cgit_enable_log_filecount * atoi(value);
         else if (cgit_repo && !strcmp(name, "repo.enable-log-linecount"))
                 cgit_repo->enable_log_linecount = cgit_enable_log_linecount * atoi(value);
         else if (cgit_repo && !strcmp(name, "repo.module-link"))
                 cgit_repo->module_link= xstrdup(value);
         else if (cgit_repo && !strcmp(name, "repo.readme") && value != NULL) {
                 if (*value == '/')
                         cgit_repo->readme = xstrdup(value);
                 else
                         cgit_repo->readme = xstrdup(fmt("%s/%s", cgit_repo->path, value));
         } else if (!strcmp(name, "include"))
                 cgit_read_config(value, cgit_global_config_cb);
 }
 
 void cgit_querystring_cb(const char *name, const char *value)
 {
         if (!strcmp(name,"r")) {
                 cgit_query_repo = xstrdup(value);
                 cgit_repo = cgit_get_repoinfo(value);
         } else if (!strcmp(name, "p")) {
                 cgit_query_page = xstrdup(value);
                 cgit_cmd = cgit_get_cmd_index(value);
         } else if (!strcmp(name, "url")) {
                 cgit_parse_url(value);
         } else if (!strcmp(name, "q")) {
                 cgit_query_search = xstrdup(value);
         } else if (!strcmp(name, "h")) {
                 cgit_query_head = xstrdup(value);
                 cgit_query_has_symref = 1;
         } else if (!strcmp(name, "id")) {
                 cgit_query_sha1 = xstrdup(value);
                 cgit_query_has_sha1 = 1;
         } else if (!strcmp(name, "id2")) {
                 cgit_query_sha2 = xstrdup(value);
                 cgit_query_has_sha1 = 1;
         } else if (!strcmp(name, "ofs")) {
                 cgit_query_ofs = atoi(value);
         } else if (!strcmp(name, "path")) {
                 cgit_query_path = trim_end(value, '/');
         } else if (!strcmp(name, "name")) {
                 cgit_query_name = xstrdup(value);
         }
 }
 
 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);
         return NULL;
 }
 
 int hextoint(char c)
 {
         if (c >= 'a' && c <= 'f')
                 return 10 + c - 'a';
         else if (c >= 'A' && c <= 'F')
                 return 10 + c - 'A';
         else if (c >= '0' && c <= '9')
                 return c - '0';
         else
                 return -1;
 }
 
 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;
 }
 
+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);
                 free(diffbuf);
                 diffbuf = NULL;
                 buflen = 0;
         }
         if (diffbuf) {
                 ((linediff_fn)priv)(diffbuf, buflen);
                 free(diffbuf);
                 diffbuf = NULL;
                 buflen = 0;
         }
         return 0;
 }
 
 int cgit_diff_files(const unsigned char *old_sha1,
                      const unsigned char *new_sha1,
                      linediff_fn fn)
 {
         mmfile_t file1, file2;
         xpparam_t diff_params;
         xdemitconf_t emit_params;
         xdemitcb_t emit_cb;
 
         if (!load_mmfile(&file1, old_sha1) || !load_mmfile(&file2, new_sha1))
                 return 1;
 
         diff_params.flags = XDF_NEED_MINIMAL;
         emit_params.ctxlen = 3;
         emit_params.flags = XDL_EMIT_FUNCNAMES;
         emit_params.find_func = NULL;
         emit_cb.outf = filediff_cb;
         emit_cb.priv = fn;
         xdl_diff(&file1, &file2, &diff_params, &emit_params, &emit_cb);
         return 0;
 }
 
 void cgit_diff_tree(const unsigned char *old_sha1,
                     const unsigned char *new_sha1,
                     filepair_fn fn, const char *prefix)
 {
         struct diff_options opt;
         int ret;
         int prefixlen;
 
         diff_setup(&opt);
         opt.output_format = DIFF_FORMAT_CALLBACK;
         opt.detect_rename = 1;
         opt.rename_limit = cgit_renamelimit;
         opt.recursive = 1;
         opt.format_callback = cgit_diff_tree_cb;
         opt.format_callback_data = fn;
         if (prefix) {
                 opt.nr_paths = 1;
                 opt.paths = &prefix;
                 prefixlen = strlen(prefix);
                 opt.pathlens = &prefixlen;
         }
         diff_setup_done(&opt);
 
         if (old_sha1 && !is_null_sha1(old_sha1))
                 ret = diff_tree_sha1(old_sha1, new_sha1, "", &opt);
         else
                 ret = diff_root_tree_sha1(new_sha1, "", &opt);
         diffcore_std(&opt);
         diff_flush(&opt);
 }
 
 void cgit_diff_commit(struct commit *commit, filepair_fn fn)
 {
         unsigned char *old_sha1 = NULL;
 
         if (commit->parents)
                 old_sha1 = commit->parents->item->object.sha1;
         cgit_diff_tree(old_sha1, commit->object.sha1, fn, NULL);
 }