Handle missing default branch and error out on invalid branch names

When no branch is specified and the repository does not have a default branch,
use the first branch.

Also, print sensible errormessages when the repository does not contain any
branches and when invalid branchnames are specified.

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

1 files changed, 58 insertions, 4 deletions

diff --git a/cgit.c b/cgit.c
index 9ca93a7..e8acc03 100644
--- a/cgit.c
+++ b/cgit.c
@@ -24,70 +24,124 @@ static int cgit_prepare_cache(struct cacheitem *item)
                 item->ttl = cgit_cache_root_ttl;
                 return 1;
         }
 
         if (!cgit_cmd) {
                 item->name = xstrdup(fmt("%s/%s/index.%s.html", cgit_cache_root,
                                          cache_safe_filename(cgit_repo->url),
                                          cache_safe_filename(cgit_querystring)));
                 item->ttl = cgit_cache_repo_ttl;
         } else {
                 item->name = xstrdup(fmt("%s/%s/%s/%s.html", cgit_cache_root,
                                          cache_safe_filename(cgit_repo->url),
                                          cgit_query_page,
                                          cache_safe_filename(cgit_querystring)));
                 if (cgit_query_has_symref)
                         item->ttl = cgit_cache_dynamic_ttl;
                 else if (cgit_query_has_sha1)
                         item->ttl = cgit_cache_static_ttl;
                 else
                         item->ttl = cgit_cache_repo_ttl;
         }
         return 1;
 }
 
+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 repoinfo *repo)
+{
+        struct refmatch info;
+
+        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;
+        else
+                return info.first_ref;
+}
+
 static void cgit_print_repo_page(struct cacheitem *item)
 {
-        char *title;
+        char *title, *tmp;
         int show_search;
-
-        if (!cgit_query_head)
-                cgit_query_head = cgit_repo->defbranch;
+        unsigned char sha1[20];
 
         if (chdir(cgit_repo->path)) {
                 title = fmt("%s - %s", cgit_root_title, "Bad request");
                 cgit_print_docstart(title, item);
                 cgit_print_pageheader(title, 0);
                 cgit_print_error(fmt("Unable to scan repository: %s",
                                      strerror(errno)));
                 cgit_print_docend();
                 return;
         }
 
         title = fmt("%s - %s", cgit_repo->name, cgit_repo->desc);
         show_search = 0;
         setenv("GIT_DIR", cgit_repo->path, 1);
 
+        if (!cgit_query_head) {
+                cgit_query_head = xstrdup(find_default_branch(cgit_repo));
+                cgit_repo->defbranch = cgit_query_head;
+        }
+
+        if (!cgit_query_head) {
+                cgit_print_docstart(title, item);
+                cgit_print_pageheader(title, 0);
+                cgit_print_error("Repository seems to be empty");
+                cgit_print_docend();
+                return;
+        }
+
+        if (get_sha1(cgit_query_head, sha1)) {
+                tmp = xstrdup(cgit_query_head);
+                cgit_query_head = cgit_repo->defbranch;
+                cgit_print_docstart(title, item);
+                cgit_print_pageheader(title, 0);
+                cgit_print_error(fmt("Invalid branch: %s", tmp));
+                cgit_print_docend();
+                return;
+        }
+
         if ((cgit_cmd == CMD_SNAPSHOT) && cgit_repo->snapshots) {
                 cgit_print_snapshot(item, cgit_query_head, cgit_query_sha1,
                                     cgit_repobasename(cgit_repo->url),
                                     cgit_query_path,
                                     cgit_repo->snapshots );
                 return;
         }
 
         if (cgit_cmd == CMD_PATCH) {
                 cgit_print_patch(cgit_query_sha1, item);
                 return;
         }
 
         if (cgit_cmd == CMD_BLOB) {
                 cgit_print_blob(item, cgit_query_sha1, cgit_query_path);
                 return;
         }
 
         show_search = (cgit_cmd == CMD_LOG);
         cgit_print_docstart(title, item);
         if (!cgit_cmd) {
                 cgit_print_pageheader("summary", show_search);
                 cgit_print_summary();
                 cgit_print_docend();