Fix segfault in patch view for root commit

The code for patch view assumed the current commit would always have a parent,
which made cgit segfault when that wasn't the case.

This fixes the bug and adds a test-script for patch view which includes a test
for the inital commit.

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

1 files changed, 5 insertions, 1 deletions

diff --git a/ui-patch.c b/ui-patch.c
index e7a010a..7ee2c41 100644
--- a/ui-patch.c
+++ b/ui-patch.c
@@ -79,25 +79,29 @@ void cgit_print_patch(char *hex, struct cacheitem *item)
                 hex = cgit_query_head;
 
         if (get_sha1(hex, sha1)) {
                 cgit_print_error(fmt("Bad object id: %s", hex));
                 return;
         }
         commit = lookup_commit_reference(sha1);
         if (!commit) {
                 cgit_print_error(fmt("Bad commit reference: %s", hex));
                 return;
         }
         info = cgit_parse_commit(commit);
-        hashcpy(old_sha1, commit->parents->item->object.sha1);
+
+        if (commit->parents && commit->parents->item)
+                hashcpy(old_sha1, commit->parents->item->object.sha1);
+        else
+                hashclr(old_sha1);
 
         patchname = fmt("%s.patch", sha1_to_hex(sha1));
         cgit_print_snapshot_start("text/plain", patchname, item);
         htmlf("From %s Mon Sep 17 00:00:00 2001\n", sha1_to_hex(sha1));
         htmlf("From: %s%s\n", info->author, info->author_email);
         html("Date: ");
         cgit_print_date(info->author_date, "%a, %d  %b  %Y  %H:%M:%S  %z%n");
         htmlf("Subject: %s\n\n", info->subject);
         if (info->msg && *info->msg) {
                 htmlf("%s", info->msg);
                 if (info->msg[strlen(info->msg) - 1] != '\n')
                         html("\n");