fix(bash): Comments false positives

In POSIX shells, the `#` needs to be after a whitespace or
start-of-line to delimit a comment. Compare:

```sh
$ echo asdf#qwert
asdf#qwert
$ echo asdf #qwert
asdf
```

I checked a few other languages as well that use #-delimited comments,
but it seems this behaviour is unique to bash and other POSIX shells.

Fixes #3917

Author: iFreilicht

CHANGES.md

@@ -5,11 +5,13 @@ Core Grammars:
 - fix(css) fix overly greedy pseudo class matching [Bradley Mackey][]
 - enh(arcade) updated to ArcGIS Arcade version 1.24 [Kristian Ekenes][]
 - fix(yaml) fix for yaml with keys having brackets highlighted incorrectly [Aneesh Kulkarni][]
+- fix(bash) fix # within token being detected as the start of a comment [Felix Uhl][]
 
 [Bradley Mackey]: https://github.com/bradleymackey
 [Kristian Ekenes]: https://github.com/ekenes
 [Aneesh Kulkarni]: https://github.com/aneesh98
 [Bruno Meneguele]: https://github.com/bmeneg
+[Felix Uhl]: https://github.com/iFreilicht
 
 
 ## Version 11.9.0

src/languages/bash.js

@@ -38,6 +38,17 @@ export default function(hljs) {
     end: /\)/,
     contains: [ hljs.BACKSLASH_ESCAPE ]
   };
+  const COMMENT = hljs.inherit(hljs.HASH_COMMENT_MODE, {
+    begin: undefined,
+    end: undefined,
+    match: [
+      /(^|\s)(?=#)/,
+      '#.*$'
+    ],
+    scope: {
+      2: 'comment'
+    },
+  });
   const HERE_DOC = {
     begin: /<<-?\s*(?=\w+)/,
     starts: { contains: [
@@ -376,7 +387,7 @@ export default function(hljs) {
       hljs.SHEBANG(), // to catch unknown shells but still highlight the shebang
       FUNCTION,
       ARITHMETIC,
-      hljs.HASH_COMMENT_MODE,
+      COMMENT,
       HERE_DOC,
       PATH_MODE,
       QUOTE_STRING,

test/markup/bash/not-comments.expect.txt

@@ -0,0 +1,3 @@
+<span class="hljs-built_in">echo</span> asdf#qwert yuiop
+
+<span class="hljs-built_in">echo</span> asdf <span class="hljs-comment">#qwert yuiop</span>

test/markup/bash/not-comments.txt

@@ -0,0 +1,3 @@
+echo asdf#qwert yuiop
+
+echo asdf #qwert yuiop