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
@@ -1,117 +1,171 @@
 /* cgit.c: cgi for the git scm
  *
  * Copyright (C) 2006 Lars Hjemli
  *
  * Licensed under GNU General Public License v2
  *   (see COPYING for full license text)
  */
 
 #include "cgit.h"
 
 static int cgit_prepare_cache(struct cacheitem *item)
 {
 	if (!cgit_repo && cgit_query_repo) {
 		char *title = fmt("%s - %s", cgit_root_title, "Bad request");
 		cgit_print_docstart(title, item);
 		cgit_print_pageheader(title, 0);
 		cgit_print_error(fmt("Unknown repo: %s", cgit_query_repo));
 		cgit_print_docend();
 		return 0;
 	}
 
 	if (!cgit_repo) {
 		item->name = xstrdup(fmt("%s/index.html", cgit_cache_root));
 		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();
 		return;
 	}
 
 	cgit_print_pageheader(cgit_query_page, show_search);
 
 	switch(cgit_cmd) {
 	case CMD_LOG:
 		cgit_print_log(cgit_query_sha1, cgit_query_ofs,
 			       cgit_max_commit_count, cgit_query_grep, cgit_query_search,
 			       cgit_query_path, 1);
 		break;
 	case CMD_TREE:
 		cgit_print_tree(cgit_query_sha1, cgit_query_path);
 		break;
 	case CMD_COMMIT:
 		cgit_print_commit(cgit_query_sha1);
 		break;
 	case CMD_REFS:
 		cgit_print_refs();
 		break;
 	case CMD_TAG:
 		cgit_print_tag(cgit_query_sha1);
 		break;
 	case CMD_DIFF: