ui-refs.c: avoid segfault on unparsed ref objects

When a ref refers to something other then a commit or tag object, cgit
could segfault when trying to display the tag info.

Noticed-by: Eugene Sajine <euguess@gmail.com>
Signed-off-by: Lars Hjemli <hjemli@gmail.com>

1 files changed, 14 insertions, 12 deletions

diff --git a/ui-refs.c b/ui-refs.c
index d3b4f6e..6571cc4 100644
--- a/ui-refs.c
+++ b/ui-refs.c
@@ -1,125 +1,127 @@
 /* ui-refs.c: browse symbolic refs
  *
  * Copyright (C) 2006 Lars Hjemli
  *
  * Licensed under GNU General Public License v2
  *   (see COPYING for full license text)
  */
 
 #include "cgit.h"
 #include "html.h"
 #include "ui-shared.h"
 
 static int header;
 
 static int cmp_age(int age1, int age2)
 {
 	if (age1 != 0 && age2 != 0)
 		return age2 - age1;
 
 	if (age1 == 0 && age2 == 0)
 		return 0;
 
 	if (age1 == 0)
 		return +1;
 
 	return -1;
 }
 
 static int cmp_ref_name(const void *a, const void *b)
 {
 	struct refinfo *r1 = *(struct refinfo **)a;
 	struct refinfo *r2 = *(struct refinfo **)b;
 
 	return strcmp(r1->refname, r2->refname);
 }
 
 static int cmp_branch_age(const void *a, const void *b)
 {
 	struct refinfo *r1 = *(struct refinfo **)a;
 	struct refinfo *r2 = *(struct refinfo **)b;
 
 	return cmp_age(r1->commit->committer_date, r2->commit->committer_date);
 }
 
+static int get_ref_age(struct refinfo *ref)
+{
+	if (!ref->object)
+		return 0;
+	switch (ref->object->type) {
+	case OBJ_TAG:
+		return ref->tag ? ref->tag->tagger_date : 0;
+	case OBJ_COMMIT:
+		return ref->commit ? ref->commit->committer_date : 0;
+	}
+	return 0;
+}
+
 static int cmp_tag_age(const void *a, const void *b)
 {
 	struct refinfo *r1 = *(struct refinfo **)a;
 	struct refinfo *r2 = *(struct refinfo **)b;
-	int r1date, r2date;
-
-	if (r1->object->type != OBJ_COMMIT)
-		r1date = r1->tag->tagger_date;
-	else
-		r1date = r1->commit->committer_date;
-
-	if (r2->object->type != OBJ_COMMIT)
-		r2date = r2->tag->tagger_date;
-	else
-		r2date = r2->commit->committer_date;
 
-	return cmp_age(r1date, r2date);
+	return cmp_age(get_ref_age(r1), get_ref_age(r2));
 }
 
 static int print_branch(struct refinfo *ref)
 {
 	struct commitinfo *info = ref->commit;
 	char *name = (char *)ref->refname;
 
 	if (!info)
 		return 1;
 	html("<tr><td>");
 	cgit_log_link(name, NULL, NULL, name, NULL, NULL, 0, NULL, NULL,
 		      ctx.qry.showmsg);
 	html("</td><td>");
 
 	if (ref->object->type == OBJ_COMMIT) {
 		cgit_commit_link(info->subject, NULL, NULL, name, NULL);
 		html("</td><td>");
 		html_txt(info->author);
 		html("</td><td colspan='2'>");
 		cgit_print_age(info->commit->date, -1, NULL);
 	} else {
 		html("</td><td></td><td>");
 		cgit_object_link(ref->object);
 	}
 	html("</td></tr>\n");
 	return 0;
 }
 
 static void print_tag_header()
 {
 	html("<tr class='nohover'><th class='left'>Tag</th>"
 	     "<th class='left'>Download</th>"
 	     "<th class='left'>Author</th>"
 	     "<th class='left' colspan='2'>Age</th></tr>\n");
 	header = 1;
 }
 
 static void print_tag_downloads(const struct cgit_repo *repo, const char *ref)
 {
 	const struct cgit_snapshot_format* f;
     	char *filename;
 	const char *basename;
 
 	if (!ref || strlen(ref) < 2)
 		return;
 
 	basename = cgit_repobasename(repo->url);
 	if (prefixcmp(ref, basename) != 0) {
 		if ((ref[0] == 'v' || ref[0] == 'V') && isdigit(ref[1]))
 			ref++;
 		if (isdigit(ref[0]))
 			ref = xstrdup(fmt("%s-%s", basename, ref));
 	}
 
 	for (f = cgit_snapshot_formats; f->suffix; f++) {
 		if (!(repo->snapshots & f->bit))
 			continue;
 		filename = fmt("%s%s", ref, f->suffix);
 		cgit_snapshot_link(filename, NULL, NULL, NULL, NULL, filename);
 		html("&nbsp;&nbsp;");
 	}
 }
 static int print_tag(struct refinfo *ref)
 {