Backfill an absent commit message

3 files changed, 36 insertions, 8 deletions

diff --git a/source/parsing.c b/source/parsing.c
index ee2b65c..a7e46de 100644
--- a/source/parsing.c
+++ b/source/parsing.c
@@ -175,14 +175,20 @@ struct commitinfo *cgit_parse_commit(struct commit *commit)
 		p = next_header_line(p);
 	while (p && *p == '\n')
 		p++;
-	if (!p)
-		return ret;
 
-	t = strchrnul(p, '\n');
-	ret->subject = substr(p, t);
-	while (*t == '\n')
-		t++;
-	ret->msg = xstrdup(t);
+	if (p) {
+		t = strchrnul(p, '\n');
+		ret->subject = substr(p, t);
+		while (*t == '\n')
+			t++;
+		ret->msg = xstrdup(t);
+	} else {
+		// A crafted commit can end right after its headers with no
+		// message. Keep subject and msg as empty strings so callers
+		// can treat them as text unconditionally.
+		ret->subject = xstrdup("");
+		ret->msg = xstrdup("");
+	}
 
 	reencode(&ret->author, ret->msg_encoding, PAGE_ENCODING);
 	reencode(&ret->author_email, ret->msg_encoding, PAGE_ENCODING);
diff --git a/source/ui-shared.c b/source/ui-shared.c
index 7687ae1..3ec4f55 100644
--- a/source/ui-shared.c
+++ b/source/ui-shared.c
@@ -436,7 +436,7 @@ void cgit_commit_link(const char *name, const char *title, const char *class,
 		html("follow=1");
 	}
 	html("'>");
-	if (name[0] != '\0') {
+	if (name && name[0] != '\0') {
 		if (strlen(name) > ctx.cfg.max_msg_len && ctx.cfg.max_msg_len >= 15) {
 			html_ntxt(name, ctx.cfg.max_msg_len - 3);
 			html("...");
diff --git a/tests/t0200-security.sh b/tests/t0200-security.sh
index 4eee9ae..83cdbfd 100644
--- a/tests/t0200-security.sh
+++ b/tests/t0200-security.sh
@@ -175,4 +175,26 @@ test_expect_success 'ssdiff percent-encodes a quoted file path' '
 	! grep "href=.[^>]*x.y.txt.[^>]*>" tmp
 '
 
+# --- A commit with no message must not crash the history views --------------
+test_expect_success 'a message-less commit renders without crashing' '
+	mkrepo repos/nomsg 1 &&
+	(
+		cd repos/nomsg &&
+		tree=$(git write-tree) &&
+		printf "tree %s\nauthor a <a@b> 1735689600 +0000\ncommitter a <a@b> 1735689600 +0000\n" "$tree" >raw &&
+		cid=$(git hash-object -t commit -w raw) &&
+		git update-ref refs/heads/master "$cid"
+	) &&
+	{
+		echo "virtual-root=/" &&
+		echo "cache-size=0" &&
+		echo "repo.url=nomsg" &&
+		echo "repo.path=$PWD/repos/nomsg/.git"
+	} >nomsgrc &&
+	CGIT_CONFIG="$PWD/nomsgrc" QUERY_STRING="url=nomsg/log/&showmsg=1" cgit >tmp &&
+	grep "no commit message" tmp &&
+	CGIT_CONFIG="$PWD/nomsgrc" QUERY_STRING="url=nomsg/" cgit >tmp &&
+	grep "no commit message" tmp
+'
+
 test_done