Be prepared for empty repositories

Before this patch, cgit would segfault on repositories with no refs.

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

2 files changed, 9 insertions, 4 deletions

diff --git a/cgit.c b/cgit.c
index 8795085..cefeddf 100644
--- a/cgit.c
+++ b/cgit.c
@@ -82,291 +82,295 @@ void config_cb(const char *name, const char *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, "robots"))
                 ctx.cfg.robots = xstrdup(value);
         else if (!strcmp(name, "clone-prefix"))
                 ctx.cfg.clone_prefix = xstrdup(value);
         else if (!strcmp(name, "repo.group"))
                 ctx.cfg.repo_group = xstrdup(value);
         else if (!strcmp(name, "repo.url"))
                 ctx.repo = cgit_add_repo(value);
         else if (!strcmp(name, "repo.name"))
                 ctx.repo->name = xstrdup(value);
         else if (ctx.repo && !strcmp(name, "repo.path"))
                 ctx.repo->path = trim_end(value, '/');
         else if (ctx.repo && !strcmp(name, "repo.clone-url"))
                 ctx.repo->clone_url = xstrdup(value);
         else if (ctx.repo && !strcmp(name, "repo.desc"))
                 ctx.repo->desc = xstrdup(value);
         else if (ctx.repo && !strcmp(name, "repo.owner"))
                 ctx.repo->owner = xstrdup(value);
         else if (ctx.repo && !strcmp(name, "repo.defbranch"))
                 ctx.repo->defbranch = xstrdup(value);
         else if (ctx.repo && !strcmp(name, "repo.snapshots"))
                 ctx.repo->snapshots = ctx.cfg.snapshots & cgit_parse_snapshots_mask(value); /* XXX: &? */
         else if (ctx.repo && !strcmp(name, "repo.enable-log-filecount"))
                 ctx.repo->enable_log_filecount = ctx.cfg.enable_log_filecount * atoi(value);
         else if (ctx.repo && !strcmp(name, "repo.enable-log-linecount"))
                 ctx.repo->enable_log_linecount = ctx.cfg.enable_log_linecount * atoi(value);
         else if (ctx.repo && !strcmp(name, "repo.module-link"))
                 ctx.repo->module_link= xstrdup(value);
         else if (ctx.repo && !strcmp(name, "repo.readme") && value != NULL) {
                 if (*value == '/')
                         ctx.repo->readme = xstrdup(value);
                 else
                         ctx.repo->readme = xstrdup(fmt("%s/%s", ctx.repo->path, value));
         } else if (!strcmp(name, "include"))
                 parse_configfile(value, config_cb);
 }
 
 static void querystring_cb(const char *name, const char *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")) {
                 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);
         }
 }
 
 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_static_ttl = -1;
         ctx->cfg.css = "/cgit.css";
         ctx->cfg.logo = "/git-logo.png";
         ctx->cfg.max_repo_count = 50;
         ctx->cfg.max_commit_count = 50;
         ctx->cfg.max_lock_attempts = 5;
         ctx->cfg.max_msg_len = 60;
         ctx->cfg.max_repodesc_len = 60;
         ctx->cfg.module_link = "./?repo=%s&page=commit&id=%s";
         ctx->cfg.renamelimit = -1;
         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->page.mimetype = "text/html";
         ctx->page.charset = PAGE_ENCODING;
         ctx->page.filename = NULL;
         ctx->page.modified = time(NULL);
         ctx->page.expires = ctx->page.modified;
 }
 
 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)
-                return info.req_ref;
+                ref = info.req_ref;
         else
-                return info.first_ref;
+                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.head = xstrdup(find_default_branch(ctx->repo));
+                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;
                 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";
                 ctx->repo = NULL;
                 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_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();
 }
 
 static void cgit_parse_args(int argc, const char **argv)
 {
         int i;
 
         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 (!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);
                 }
         }
 }
 
 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 *cgit_config_env = getenv("CGIT_CONFIG");
         int err, ttl;
 
         prepare_context(&ctx);
         cgit_repolist.length = 0;
         cgit_repolist.count = 0;
         cgit_repolist.repos = NULL;
 
         parse_configfile(cgit_config_env ? cgit_config_env : CGIT_CONFIG,
diff --git a/ui-shared.c b/ui-shared.c
index 209af6e..4280a70 100644
--- a/ui-shared.c
+++ b/ui-shared.c
@@ -393,257 +393,258 @@ void cgit_print_age(time_t t, time_t max_relative, char *format)
                 htmlf("<span class='age-days'>%.0f days</span>",
                       secs * 1.0 / TM_DAY);
                 return;
         }
         if (secs < TM_MONTH * 2) {
                 htmlf("<span class='age-weeks'>%.0f weeks</span>",
                       secs * 1.0 / TM_WEEK);
                 return;
         }
         if (secs < TM_YEAR * 2) {
                 htmlf("<span class='age-months'>%.0f months</span>",
                       secs * 1.0 / TM_MONTH);
                 return;
         }
         htmlf("<span class='age-years'>%.0f years</span>",
               secs * 1.0 / TM_YEAR);
 }
 
 void cgit_print_http_headers(struct cgit_context *ctx)
 {
         if (ctx->page.mimetype && ctx->page.charset)
                 htmlf("Content-Type: %s; charset=%s\n", ctx->page.mimetype,
                       ctx->page.charset);
         else if (ctx->page.mimetype)
                 htmlf("Content-Type: %s\n", ctx->page.mimetype);
         if (ctx->page.filename)
                 htmlf("Content-Disposition: inline; filename=\"%s\"\n",
                       ctx->page.filename);
         htmlf("Last-Modified: %s\n", http_date(ctx->page.modified));
         htmlf("Expires: %s\n", http_date(ctx->page.expires));
         html("\n");
 }
 
 void cgit_print_docstart(struct cgit_context *ctx)
 {
         html(cgit_doctype);
         html("<html xmlns='http://www.w3.org/1999/xhtml' xml:lang='en' lang='en'>\n");
         html("<head>\n");
         html("<title>");
         html_txt(ctx->page.title);
         html("</title>\n");
         htmlf("<meta name='generator' content='cgit %s'/>\n", cgit_version);
         if (ctx->cfg.robots && *ctx->cfg.robots)
                 htmlf("<meta name='robots' content='%s'/>\n", ctx->cfg.robots);
         html("<link rel='stylesheet' type='text/css' href='");
         html_attr(ctx->cfg.css);
         html("'/>\n");
         if (ctx->cfg.favicon) {
                 html("<link rel='shortcut icon' href='");
                 html_attr(ctx->cfg.favicon);
                 html("'/>\n");
         }
         html("</head>\n");
         html("<body>\n");
 }
 
 void cgit_print_docend()
 {
         html("</div>");
         if (ctx.cfg.footer)
                 html_include(ctx.cfg.footer);
         else {
                 html("<div class='footer'>generated ");
                 cgit_print_date(time(NULL), FMT_LONGDATE);
                 htmlf(" by cgit %s", cgit_version);
                 html("</div>\n");
         }
         html("</body>\n</html>\n");
 }
 
 int print_branch_option(const char *refname, const unsigned char *sha1,
                         int flags, void *cb_data)
 {
         char *name = (char *)refname;
         html_option(name, name, ctx.qry.head);
         return 0;
 }
 
 int print_archive_ref(const char *refname, const unsigned char *sha1,
                        int flags, void *cb_data)
 {
         struct tag *tag;
         struct taginfo *info;
         struct object *obj;
         char buf[256], *url;
         unsigned char fileid[20];
         int *header = (int *)cb_data;
 
         if (prefixcmp(refname, "refs/archives"))
                 return 0;
         strncpy(buf, refname+14, sizeof(buf));
         obj = parse_object(sha1);
         if (!obj)
                 return 1;
         if (obj->type == OBJ_TAG) {
                 tag = lookup_tag(sha1);
                 if (!tag || parse_tag(tag) || !(info = cgit_parse_tag(tag)))
                         return 0;
                 hashcpy(fileid, tag->tagged->sha1);
         } else if (obj->type != OBJ_BLOB) {
                 return 0;
         } else {
                 hashcpy(fileid, sha1);
         }
         if (!*header) {
                 html("<h1>download</h1>\n");
                 *header = 1;
         }
         url = cgit_pageurl(ctx.qry.repo, "blob",
                            fmt("id=%s&amp;path=%s", sha1_to_hex(fileid),
                                buf));
         html_link_open(url, NULL, "menu");
         html_txt(strlpart(buf, 20));
         html_link_close();
         return 0;
 }
 
 void add_hidden_formfields(int incl_head, int incl_search, char *page)
 {
         char *url;
 
         if (!ctx.cfg.virtual_root) {
                 url = fmt("%s/%s", ctx.qry.repo, page);
                 if (ctx.qry.path)
                         url = fmt("%s/%s", url, ctx.qry.path);
                 html_hidden("url", url);
         }
 
-        if (incl_head && strcmp(ctx.qry.head, ctx.repo->defbranch))
+        if (incl_head && ctx.qry.head && ctx.repo->defbranch &&
+            strcmp(ctx.qry.head, ctx.repo->defbranch))
                 html_hidden("h", ctx.qry.head);
 
         if (ctx.qry.sha1)
                 html_hidden("id", ctx.qry.sha1);
         if (ctx.qry.sha2)
                 html_hidden("id2", ctx.qry.sha2);
 
         if (incl_search) {
                 if (ctx.qry.grep)
                         html_hidden("qt", ctx.qry.grep);
                 if (ctx.qry.search)
                         html_hidden("q", ctx.qry.search);
         }
 }
 
 char *hc(struct cgit_cmd *cmd, const char *page)
 {
         return (strcmp(cmd->name, page) ? NULL : "active");
 }
 
 void cgit_print_pageheader(struct cgit_context *ctx)
 {
         struct cgit_cmd *cmd = cgit_get_cmd(ctx);
 
         html("<table id='header'>\n");
         html("<tr>\n");
         html("<td class='logo' rowspan='2'><a href='");
         if (ctx->cfg.logo_link)
                 html_attr(ctx->cfg.logo_link);
         else
                 html_attr(cgit_rooturl());
         html("'><img src='");
         html_attr(ctx->cfg.logo);
         html("' alt='cgit logo'/></a></td>\n");
 
         html("<td class='main'>");
         if (ctx->repo) {
                 cgit_index_link("index", NULL, NULL, NULL, 0);
                 html(" : ");
                 reporevlink(NULL, ctx->repo->name, NULL, hc(cmd, "summary"),
                             ctx->qry.head, NULL, NULL);
                 html("</td><td class='form'>");
                 html("<form method='get' action=''>\n");
                 add_hidden_formfields(0, 1, ctx->qry.page);
                 html("<select name='h' onchange='this.form.submit();'>\n");
                 for_each_branch_ref(print_branch_option, ctx->qry.head);
                 html("</select> ");
                 html("<input type='submit' name='' value='switch'/>");
                 html("</form>");
         } else
                 html_txt(ctx->cfg.root_title);
         html("</td></tr>\n");
 
         html("<tr><td class='sub'>");
         if (ctx->repo) {
                 html_txt(ctx->repo->desc);
                 html("</td><td class='sub right'>");
                 html_txt(ctx->repo->owner);
         } else {
                 if (ctx->cfg.root_desc)
                         html_txt(ctx->cfg.root_desc);
                 else if (ctx->cfg.index_info)
                         html_include(ctx->cfg.index_info);
         }
         html("</td></tr></table>\n");
 
         html("<table class='tabs'><tr><td>\n");
         if (ctx->repo) {
                 reporevlink(NULL, "summary", NULL, hc(cmd, "summary"),
                             ctx->qry.head, NULL, NULL);
                 cgit_refs_link("refs", NULL, hc(cmd, "refs"), ctx->qry.head,
                                ctx->qry.sha1, NULL);
                 cgit_log_link("log", NULL, hc(cmd, "log"), ctx->qry.head,
                               NULL, NULL, 0, NULL, NULL);
                 cgit_tree_link("tree", NULL, hc(cmd, "tree"), ctx->qry.head,
                                ctx->qry.sha1, NULL);
                 cgit_commit_link("commit", NULL, hc(cmd, "commit"),
                                  ctx->qry.head, ctx->qry.sha1);
                 cgit_diff_link("diff", NULL, hc(cmd, "diff"), ctx->qry.head,
                                ctx->qry.sha1, ctx->qry.sha2, NULL);
                 if (ctx->repo->readme)
                         reporevlink("about", "about", NULL,
                                     hc(cmd, "about"), ctx->qry.head, NULL,
                                     NULL);
                 html("</td><td class='form'>");
                 html("<form class='right' method='get' action='");
                 if (ctx->cfg.virtual_root)
                         html_attr(cgit_fileurl(ctx->qry.repo, "log",
                                                ctx->qry.path, NULL));
                 html("'>\n");
                 add_hidden_formfields(1, 0, "log");
                 html("<select name='qt'>\n");
                 html_option("grep", "log msg", ctx->qry.grep);
                 html_option("author", "author", ctx->qry.grep);
                 html_option("committer", "committer", ctx->qry.grep);
                 html("</select>\n");
                 html("<input class='txt' type='text' size='10' name='q' value='");
                 html_attr(ctx->qry.search);
                 html("'/>\n");
                 html("<input type='submit' value='search'/>\n");
                 html("</form>\n");
         } else {
                 site_link(NULL, "index", NULL, hc(cmd, "repolist"), NULL, 0);
                 if (ctx->cfg.root_readme)
                         site_link("about", "about", NULL, hc(cmd, "about"),
                                   NULL, 0);
                 html("</td><td class='form'>");
                 html("<form method='get' action='");
                 html_attr(cgit_rooturl());
                 html("'>\n");
                 html("<input type='text' name='q' size='10' value='");
                 html_attr(ctx->qry.search);
                 html("'/>\n");
                 html("<input type='submit' value='search'/>\n");
                 html("</form>");
         }
         html("</td></tr></table>\n");
         html("<div class='content'>");
 }
 
 void cgit_print_filemode(unsigned short mode)
 {
         if (S_ISDIR(mode))
                 html("d");
         else if (S_ISLNK(mode))
                 html("l");
         else if (S_ISGITLINK(mode))
                 html("m");