Handle empty/malformed commit messages

An empty commit message would trigger a segfault in the current
cgit_parse_commit().

Also, make sure that all char-pointers are properly initialized.

1 files changed, 13 insertions, 6 deletions

diff --git a/parsing.c b/parsing.c
index 4173dd4..4412dee 100644
--- a/parsing.c
+++ b/parsing.c
@@ -124,68 +124,75 @@ int cgit_parse_query(char *txt, configfn fn)
 		t++;
 	}
 	if (t!=txt)
 		(*fn)(txt, value);
 	return 0;
 }
 
 char *substr(const char *head, const char *tail)
 {
 	char *buf;
 
 	buf = xmalloc(tail - head + 1);
 	strncpy(buf, head, tail - head);
 	buf[tail - head] = '\0';
 	return buf;
 }
 
 struct commitinfo *cgit_parse_commit(struct commit *commit)
 {
 	struct commitinfo *ret;
 	char *p = commit->buffer, *t = commit->buffer;
 
 	ret = xmalloc(sizeof(*ret));
 	ret->commit = commit;
+	ret->author = NULL;
+	ret->author_email = NULL;
+	ret->committer = NULL;
+	ret->committer_email = NULL;
+	ret->subject = NULL;
+	ret->msg = NULL;
 
 	if (strncmp(p, "tree ", 5))
 		die("Bad commit: %s", sha1_to_hex(commit->object.sha1));
 	else
 		p += 46; // "tree " + hex[40] + "\n"
 
 	while (!strncmp(p, "parent ", 7))
 		p += 48; // "parent " + hex[40] + "\n"
 
 	if (!strncmp(p, "author ", 7)) {
 		p += 7;
 		t = strchr(p, '<') - 1;
 		ret->author = substr(p, t);
 		p = t;
 		t = strchr(t, '>') + 1;
 		ret->author_email = substr(p, t);
 		ret->author_date = atol(++t);
 		p = strchr(t, '\n') + 1;
 	}
 
 	if (!strncmp(p, "committer ", 9)) {
 		p += 9;
 		t = strchr(p, '<') - 1;
 		ret->committer = substr(p, t);
 		p = t;
 		t = strchr(t, '>') + 1;
 		ret->committer_email = substr(p, t);
 		ret->committer_date = atol(++t);
 		p = strchr(t, '\n') + 1;
 	}
 
 	while (*p == '\n')
 		p = strchr(p, '\n') + 1;
 
 	t = strchr(p, '\n');
-	ret->subject = substr(p, t);
-	p = t + 1;
-
-	while (*p == '\n')
-		p = strchr(p, '\n') + 1;
-	ret->msg = p;
+	if (t && *t) {
+		ret->subject = substr(p, t);
+		p = t + 1;
 
+		while (*p == '\n')
+			p = strchr(p, '\n') + 1;
+		ret->msg = p;
+	}
 	return ret;
 }