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
@@ -1,110 +1,114 @@
 /* ui-patch.c: generate patch view
  *
  * Copyright (C) 2007 Lars Hjemli
  *
  * Licensed under GNU General Public License v2
  *   (see COPYING for full license text)
  */
 
 #include "cgit.h"
 
 static void print_line(char *line, int len)
 {
         char c = line[len-1];
 
         line[len-1] = '\0';
         htmlf("%s\n", line);
         line[len-1] = c;
 }
 
 static void header(unsigned char *sha1, char *path1, int mode1,
                    unsigned char *sha2, char *path2, int mode2)
 {
         char *abbrev1, *abbrev2;
         int subproject;
 
         subproject = (S_ISGITLINK(mode1) || S_ISGITLINK(mode2));
         htmlf("diff --git a/%s b/%s\n", path1, path2);
 
         if (is_null_sha1(sha1))
                 path1 = "dev/null";
         if (is_null_sha1(sha2))
                 path2 = "dev/null";
 
         if (mode1 == 0)
                 htmlf("new file mode %.6o\n", mode2);
 
         if (mode2 == 0)
                 htmlf("deleted file mode %.6o\n", mode1);
 
         if (!subproject) {
                 abbrev1 = xstrdup(find_unique_abbrev(sha1, DEFAULT_ABBREV));
                 abbrev2 = xstrdup(find_unique_abbrev(sha2, DEFAULT_ABBREV));
                 htmlf("index %s..%s", abbrev1, abbrev2);
                 free(abbrev1);
                 free(abbrev2);
                 if (mode1 != 0 && mode2 != 0) {
                         htmlf(" %.6o", mode1);
                         if (mode2 != mode1)
                                 htmlf("..%.6o", mode2);
                 }
                 htmlf("\n--- a/%s\n", path1);
                 htmlf("+++ b/%s\n", path2);
         }
 }
 
 static void filepair_cb(struct diff_filepair *pair)
 {
         header(pair->one->sha1, pair->one->path, pair->one->mode,
                pair->two->sha1, pair->two->path, pair->two->mode);
         if (S_ISGITLINK(pair->one->mode) || S_ISGITLINK(pair->two->mode)) {
                 if (S_ISGITLINK(pair->one->mode))
                         print_line(fmt("-Subproject %s", sha1_to_hex(pair->one->sha1)), 52);
                 if (S_ISGITLINK(pair->two->mode))
                         print_line(fmt("+Subproject %s", sha1_to_hex(pair->two->sha1)), 52);
                 return;
         }
         if (cgit_diff_files(pair->one->sha1, pair->two->sha1, print_line))
                 html("Error running diff");
 }
 
 void cgit_print_patch(char *hex, struct cacheitem *item)
 {
         struct commit *commit;
         struct commitinfo *info;
         unsigned char sha1[20], old_sha1[20];
         char *patchname;
 
         if (!hex)
                 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");
         }
         html("---\n");
         cgit_diff_tree(old_sha1, sha1, filepair_cb, NULL);
         html("--\n");
         htmlf("cgit %s\n", CGIT_VERSION);
         cgit_free_commitinfo(info);
 }