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
@@ -1,264 +1,318 @@
 /* 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:
 		cgit_print_diff(cgit_query_sha1, cgit_query_sha2, cgit_query_path);
 		break;
 	default:
 		cgit_print_error("Invalid request");
 	}
 	cgit_print_docend();
 }
 
 static void cgit_fill_cache(struct cacheitem *item, int use_cache)
 {
 	static char buf[PATH_MAX];
 	int stdout2;
 
 	getcwd(buf, sizeof(buf));
 	item->st.st_mtime = time(NULL);
 
 	if (use_cache) {
 		stdout2 = chk_positive(dup(STDOUT_FILENO),
 				       "Preserving STDOUT");
 		chk_zero(close(STDOUT_FILENO), "Closing STDOUT");
 		chk_positive(dup2(item->fd, STDOUT_FILENO), "Dup2(cachefile)");
 	}
 
 	if (cgit_repo)
 		cgit_print_repo_page(item);
 	else
 		cgit_print_repolist(item);
 
 	if (use_cache) {
 		chk_zero(close(STDOUT_FILENO), "Close redirected STDOUT");
 		chk_positive(dup2(stdout2, STDOUT_FILENO),
 			     "Restoring original STDOUT");
 		chk_zero(close(stdout2), "Closing temporary STDOUT");
 	}
 
 	chdir(buf);
 }
 
 static void cgit_check_cache(struct cacheitem *item)
 {
 	int i = 0;
 
  top:
 	if (++i > cgit_max_lock_attempts) {
 		die("cgit_refresh_cache: unable to lock %s: %s",
 		    item->name, strerror(errno));
 	}
 	if (!cache_exist(item)) {
 		if (!cache_lock(item)) {
 			sleep(1);
 			goto top;
 		}
 		if (!cache_exist(item)) {
 			cgit_fill_cache(item, 1);
 			cache_unlock(item);
 		} else {
 			cache_cancel_lock(item);
 		}
 	} else if (cache_expired(item) && cache_lock(item)) {
 		if (cache_expired(item)) {
 			cgit_fill_cache(item, 1);
 			cache_unlock(item);
 		} else {
 			cache_cancel_lock(item);
 		}
 	}
 }
 
 static void cgit_print_cache(struct cacheitem *item)
 {
 	static char buf[4096];
 	ssize_t i;
 
 	int fd = open(item->name, O_RDONLY);
 	if (fd<0)
 		die("Unable to open cached file %s", item->name);
 
 	while((i=read(fd, buf, sizeof(buf))) > 0)
 		write(STDOUT_FILENO, buf, i);
 
 	close(fd);
 }
 
 static void cgit_parse_args(int argc, const char **argv)
 {
 	int i;
 
 	for (i = 1; i < argc; i++) {
 		if (!strncmp(argv[i], "--cache=", 8)) {
 			cgit_cache_root = xstrdup(argv[i]+8);
 		}
 		if (!strcmp(argv[i], "--nocache")) {
 			cgit_nocache = 1;
 		}
 		if (!strncmp(argv[i], "--query=", 8)) {
 			cgit_querystring = xstrdup(argv[i]+8);
 		}
 		if (!strncmp(argv[i], "--repo=", 7)) {
 			cgit_query_repo = xstrdup(argv[i]+7);
 		}
 		if (!strncmp(argv[i], "--page=", 7)) {
 			cgit_query_page = xstrdup(argv[i]+7);
 		}
 		if (!strncmp(argv[i], "--head=", 7)) {
 			cgit_query_head = xstrdup(argv[i]+7);
 			cgit_query_has_symref = 1;
 		}
 		if (!strncmp(argv[i], "--sha1=", 7)) {
 			cgit_query_sha1 = xstrdup(argv[i]+7);
 			cgit_query_has_sha1 = 1;
 		}
 		if (!strncmp(argv[i], "--ofs=", 6)) {
 			cgit_query_ofs = atoi(argv[i]+6);
 		}
 	}
 }
 
 int main(int argc, const char **argv)
 {
 	struct cacheitem item;
 	const char *cgit_config_env = getenv("CGIT_CONFIG");
 
 	htmlfd = STDOUT_FILENO;
 	item.st.st_mtime = time(NULL);
 	cgit_repolist.length = 0;
 	cgit_repolist.count = 0;
 	cgit_repolist.repos = NULL;
 
 	cgit_read_config(cgit_config_env ? cgit_config_env : CGIT_CONFIG,
 			 cgit_global_config_cb);
 	cgit_repo = NULL;
 	if (getenv("SCRIPT_NAME"))
 		cgit_script_name = xstrdup(getenv("SCRIPT_NAME"));
 	if (getenv("QUERY_STRING"))
 		cgit_querystring = xstrdup(getenv("QUERY_STRING"));
 	cgit_parse_args(argc, argv);
 	cgit_parse_query(cgit_querystring, cgit_querystring_cb);
 	if (!cgit_prepare_cache(&item))
 		return 0;
 	if (cgit_nocache) {
 		cgit_fill_cache(&item, 0);
 	} else {
 		cgit_check_cache(&item);
 		cgit_print_cache(&item);
 	}
 	return 0;
 }