fix(yaml) empty lines should not terminate block scalars

CHANGES.md

@@ -14,6 +14,7 @@ Core Grammars:
 - fix(c, cpp) stop a raw string's closing delimiter from swallowing quotes, which broke highlighting of everything after the literal, issue #3585 [David Pavlovschii][]
 - enh(python) add missing builtins: `aiter` and `anext` (Python 3.10), `frozendict` and `sentinel` (Python 3.15) [Hugo van Kemenade][]
 - enh(python) Support t-strings [Nicolas Le Cam][]
+- fix(yaml) stop empty lines from ending a block scalar (`|`/`>`), which caused the rest of the string to be re-parsed as YAML, issue #4090 [pikammmmm][]
 
 Documentation:
 
@@ -33,6 +34,7 @@ CONTRIBUTORS
 [Nicolas Le Cam]: https://github.com/KuSh
 [Konstantin Baltsat]: https://github.com/Baltsat
 [David Pavlovschii]: https://github.com/davidpavlovschi
+[pikammmmm]: https://github.com/pikammmmm
 
 
 ## Version 11.11.3

src/languages/yaml.js

@@ -136,8 +136,12 @@ export default function(hljs) {
       //
       // Indentation of subsequent lines must be the same to
       // be considered part of the block
+      //
+      // Empty lines (and lines containing only spaces) do not end the block,
+      // they are part of its content - but only when another indented line
+      // follows, so that blank lines trailing the block are left alone.
       className: 'string',
-      begin: '[\\|>]([1-9]?[+-])?[ ]*\\n( +)[^ ][^\\n]*\\n(\\2[^\\n]+\\n?)*'
+      begin: '[\\|>]([1-9]?[+-])?[ ]*\\n(?:[ ]*\\n)*( +)[^ ][^\\n]*\\n((?:[ ]*\\n)*\\2[^\\n]+\\n?)*'
     },
     { // Ruby/Rails erb
       begin: '<%[%=-]?',

test/markup/yaml/block_empty_lines.expect.txt

@@ -0,0 +1,26 @@
+<span class="hljs-attr">nested:</span>
+  <span class="hljs-attr">literal:</span> <span class="hljs-string">|
+    still: a string
+
+    not: anymore
+</span><span class="hljs-attr">folded:</span> <span class="hljs-string">&gt;
+  first line
+
+  second line
+</span><span class="hljs-attr">leading-blank:</span> <span class="hljs-string">|
+
+  alpha
+  beta
+</span><span class="hljs-attr">blank-has-spaces:</span> <span class="hljs-string">|
+  alpha
+
+  beta
+</span><span class="hljs-attr">multiple-blanks:</span> <span class="hljs-string">|
+  alpha
+
+
+  beta
+</span><span class="hljs-attr">trailing-blank:</span> <span class="hljs-string">|
+  alpha
+</span>
+<span class="hljs-attr">next_key:</span> <span class="hljs-string">after</span>

test/markup/yaml/block_empty_lines.txt

@@ -0,0 +1,26 @@
+nested:
+  literal: |
+    still: a string
+
+    not: anymore
+folded: >
+  first line
+
+  second line
+leading-blank: |
+
+  alpha
+  beta
+blank-has-spaces: |
+  alpha
+
+  beta
+multiple-blanks: |
+  alpha
+
+
+  beta
+trailing-blank: |
+  alpha
+
+next_key: after