Add Goldmark as the new default markdown handler

This commit adds the fast and CommonMark compliant Goldmark as the new default markdown handler in Hugo.

If you want to continue using BlackFriday as the default for md/markdown extensions, you can use this configuration:

```toml
[markup]
defaultMarkdownHandler="blackfriday"
```

Fixes #5963
Fixes #1778
Fixes #6355

1 files changed, 13 insertions, 5 deletions

diff --git a/hugolib/page__per_output.go b/hugolib/page__per_output.go
index ef2419eca..59de10be3 100644
--- a/hugolib/page__per_output.go
+++ b/hugolib/page__per_output.go
@@ -77,7 +77,7 @@ func newPageContentOutput(p *pageState) func(f output.Format) (*pageContentOutpu
 				// See https://github.com/gohugoio/hugo/issues/6210
 				if r := recover(); r != nil {
 					err = fmt.Errorf("%s", r)
-					p.s.Log.ERROR.Println("[BUG] Got panic:\n", string(debug.Stack()))
+					p.s.Log.ERROR.Printf("[BUG] Got panic:\n%s\n%s", r, string(debug.Stack()))
 				}
 			}()
 
@@ -103,11 +103,14 @@ func newPageContentOutput(p *pageState) func(f output.Format) (*pageContentOutpu
 					if err != nil {
 						return err
 					}
+					cp.convertedResult = r
 					cp.workContent = r.Bytes()
 
-					tmpContent, tmpTableOfContents := helpers.ExtractTOC(cp.workContent)
-					cp.tableOfContents = helpers.BytesToHTML(tmpTableOfContents)
-					cp.workContent = tmpContent
+					if _, ok := r.(converter.TableOfContentsProvider); !ok {
+						tmpContent, tmpTableOfContents := helpers.ExtractTOC(cp.workContent)
+						cp.tableOfContents = helpers.BytesToHTML(tmpTableOfContents)
+						cp.workContent = tmpContent
+					}
 				}
 
 				if cp.placeholdersEnabled {
@@ -223,7 +226,8 @@ type pageContentOutput struct {
 
 	// Content state
 
-	workContent []byte
+	workContent     []byte
+	convertedResult converter.Result
 
 	// Temporary storage of placeholders mapped to their content.
 	// These are shortcodes etc. Some of these will need to be replaced
@@ -284,6 +288,10 @@ func (p *pageContentOutput) Summary() template.HTML {
 
 func (p *pageContentOutput) TableOfContents() template.HTML {
 	p.p.s.initInit(p.initMain, p.p)
+	if tocProvider, ok := p.convertedResult.(converter.TableOfContentsProvider); ok {
+		cfg := p.p.s.ContentSpec.Converters.GetMarkupConfig()
+		return template.HTML(tocProvider.TableOfContents().ToHTML(cfg.TableOfContents.StartLevel, cfg.TableOfContents.EndLevel))
+	}
 	return p.tableOfContents
 }