Remove visitLinksForShortLinks features (#6257)

The visitLinksForShortLinks feature would look inside of an <a> tag and
run shortLinkProcessorFull on any text, which attempts to create links
out of potential 'short links' like [[test]] [[link|example]] etc...
This makes no sense because you can't have nested links within an <a>
tag. Specifically, the html5 standard says <a> tags can't include
interactive content if they contain the href attribute:

 http://w3c.github.io/html/single-page.html#the-a-element

And also defines an <a> element with a href attribute as interactive:

 http://w3c.github.io/html/single-page.html#interactive-content

Therefore you can't really put a link inside of another link. In
practice none of this works anyways since browsers won't render it, it
would probably be broken if they tried, and it is causing a bug
(#4946). No current tests rely on this behavior either.

This removes the feature and also explicitly excludes the
current visitNodeForShortLinks from looking in <a> tags.

diff --git a/modules/markup/html.go b/modules/markup/html.go
index 8ce8740748810de9d0b59a79764ae75b133b9a7e..dab6d4e8e5f2b5e34f809045f92ff7bf22a4e7d5 100644 (file)
--- a/modules/markup/html.go
+++ b/modules/markup/html.go
@@ -171,11 +171,6 @@ type postProcessCtx struct {
 
        // processors used by this context.
        procs []processor
-
-       // if set to true, when an <a> is found, instead of just returning during
-       // visitNode, it will recursively visit the node exclusively running
-       // shortLinkProcessorFull with true.
-       visitLinksForShortLinks bool
 }
 
 // PostProcess does the final required transformations to the passed raw HTML
@@ -191,11 +186,10 @@ func PostProcess(
 ) ([]byte, error) {
        // create the context from the parameters
        ctx := &postProcessCtx{
-               metas:                   metas,
-               urlPrefix:               urlPrefix,
-               isWikiMarkdown:          isWikiMarkdown,
-               procs:                   defaultProcessors,
-               visitLinksForShortLinks: true,
+               metas:          metas,
+               urlPrefix:      urlPrefix,
+               isWikiMarkdown: isWikiMarkdown,
+               procs:          defaultProcessors,
        }
        return ctx.postProcess(rawHTML)
 }
@@ -285,9 +279,6 @@ func (ctx *postProcessCtx) visitNode(node *html.Node) {
                ctx.textNode(node)
        case html.ElementNode:
                if node.Data == "a" || node.Data == "code" || node.Data == "pre" {
-                       if node.Data == "a" && ctx.visitLinksForShortLinks {
-                               ctx.visitNodeForShortLinks(node)
-                       }
                        return
                }
                for n := node.FirstChild; n != nil; n = n.NextSibling {
@@ -302,7 +293,7 @@ func (ctx *postProcessCtx) visitNodeForShortLinks(node *html.Node) {
        case html.TextNode:
                shortLinkProcessorFull(ctx, node, true)
        case html.ElementNode:
-               if node.Data == "code" || node.Data == "pre" {
+               if node.Data == "code" || node.Data == "pre" || node.Data == "a" {
                        return
                }
                for n := node.FirstChild; n != nil; n = n.NextSibling {

diff --git a/modules/markup/html_test.go b/modules/markup/html_test.go
index f17d00cd67e68d3c4aaeaf20d0a67c9f60832a94..f430cb04bef5b2452282ecea6fecd36154370b9c 100644 (file)
--- a/modules/markup/html_test.go
+++ b/modules/markup/html_test.go
@@ -222,4 +222,8 @@ func TestRender_ShortLinks(t *testing.T) {
                "[[some/path/Link #.jpg]]",
                `<p><a href="`+notencodedImgurl+`" rel="nofollow"><img src="`+notencodedImgurl+`"/></a></p>`,
                `<p><a href="`+notencodedImgurlWiki+`" rel="nofollow"><img src="`+notencodedImgurlWiki+`"/></a></p>`)
+       test(
+               "<p><a href=\"https://example.org\">[[foobar]]</a></p>",
+               `<p><a href="https://example.org" rel="nofollow">[[foobar]]</a></p>`,
+               `<p><a href="https://example.org" rel="nofollow">[[foobar]]</a></p>`)
 }