markup/goldmark/codeblocks: Fix slice bounds out of range

For the Position in code blocks we try to match the .Inner with the original source. This isn't always possible.

This commits avoids panics in these situations.

Fixes #9627

diff --git a/hugolib/page.go b/hugolib/page.go
index 175e1fc3b0c0c1874fe2515fb6e066a547167289..c4f30de9dfb9391a874cdef7c8d0ffeda0c13ddc 100644 (file)
--- a/hugolib/page.go
+++ b/hugolib/page.go
@@ -784,6 +784,11 @@ func (p *pageState) posFromPage(offset int) text.Position {
 }
 
 func (p *pageState) posFromInput(input []byte, offset int) text.Position {
+       if offset < 0 {
+               return text.Position{
+                       Filename: p.pathOrTitle(),
+               }
+       }
        lf := []byte("\n")
        input = input[:offset]
        lineNumber := bytes.Count(input, lf) + 1

diff --git a/markup/goldmark/codeblocks/integration_test.go b/markup/goldmark/codeblocks/integration_test.go
index 1a70b0bf0abb03b9093c0931e9625391f50482c0..7362ef2976a4578c03934404a4d4db53c569a663 100644 (file)
--- a/markup/goldmark/codeblocks/integration_test.go
+++ b/markup/goldmark/codeblocks/integration_test.go
@@ -164,6 +164,43 @@ fmt.Println("Hello, World!");
        )
 }
 
+func TestCodeblocksBugs(t *testing.T) {
+       t.Parallel()
+
+       files := `
+-- config.toml --
+-- layouts/_default/_markup/render-codeblock.html --
+{{ .Position | safeHTML }}
+-- layouts/_default/single.html --
+{{ .Content }}
+-- content/p1.md --
+---
+title: "p1"
+---
+
+## Issue 9627
+
+§§§text
+{{</* foo */>}}
+§§§
+
+`
+
+       b := hugolib.NewIntegrationTestBuilder(
+               hugolib.IntegrationTestConfig{
+                       T:           t,
+                       TxtarString: files,
+                       NeedsOsFS:   false,
+               },
+       ).Build()
+
+       b.AssertFileContent("public/p1/index.html", `
+# Issue 9627: For the Position in code blocks we try to match the .Inner with the original source. This isn't always possible.
+p1.md:0:0
+       `,
+       )
+}
+
 func TestCodeChomp(t *testing.T) {
        t.Parallel()