diff --git a/modules/markup/html.go b/modules/markup/html.go
index 827be1a9a..345c99e3b 100644
--- a/modules/markup/html.go
+++ b/modules/markup/html.go
@@ -55,7 +55,7 @@ var (
anySHA1Pattern = regexp.MustCompile(`https?://(?:\S+/){4,5}([0-9a-f]{40})(/[-+~_%.a-zA-Z0-9/]+)?(#[-+~_%.a-zA-Z0-9]+)?`)
// comparePattern matches "http://domain/org/repo/compare/COMMIT1...COMMIT2#hash"
- comparePattern = regexp.MustCompile(`https?://(?:\S+/){4,5}([0-9a-f]{40})(\.\.\.?)([0-9a-f]{40})?(#[-+~_%.a-zA-Z0-9]+)?`)
+ comparePattern = regexp.MustCompile(`https?://(?:\S+/){4,5}([0-9a-f]{7,40})(\.\.\.?)([0-9a-f]{7,40})?(#[-+~_%.a-zA-Z0-9]+)?`)
validLinksPattern = regexp.MustCompile(`^[a-z][\w-]+://`)
@@ -944,6 +944,13 @@ func comparePatternProcessor(ctx *RenderContext, node *html.Node) {
return
}
+ // Ensure that every group (m[0]...m[7]) has a match
+ for i := 0; i < 8; i++ {
+ if m[i] == -1 {
+ return
+ }
+ }
+
urlFull := node.Data[m[0]:m[1]]
text1 := base.ShortSha(node.Data[m[2]:m[3]])
textDots := base.ShortSha(node.Data[m[4]:m[5]])
diff --git a/modules/markup/html_test.go b/modules/markup/html_test.go
index 3fd9ef9f8..23d7b4457 100644
--- a/modules/markup/html_test.go
+++ b/modules/markup/html_test.go
@@ -546,3 +546,16 @@ func TestFuzz(t *testing.T) {
assert.NoError(t, err)
}
+
+func TestIssue18471(t *testing.T) {
+ data := `http://domain/org/repo/compare/783b039...da951ce`
+
+ var res strings.Builder
+ err := PostProcess(&RenderContext{
+ URLPrefix: "https://example.com",
+ Metas: localMetas,
+ }, strings.NewReader(data), &res)
+
+ assert.NoError(t, err)
+ assert.Equal(t, res.String(), "783b039...da951ce
")
+}