vim-patch:71149df: runtime(java): Dismiss "g:markdown_fenced_languages" for Java buffers (neovim#35596)

No support is provided or planned for language recognition
in code snippets of documentation comments.  Requesting to
load arbitrary syntax plugins with the aid of the concerned
variable is therefore wasteful in general and erroneous when
paired languages ":syn-include" one another without taking
steps to manage circularity.

related: vim/vim#17308
related: vim/vim#17220
closes: vim/vim#18172

vim/vim@71149df

Co-authored-by: Aliaksei Budavei <[email protected]>

Author: zeertzjq

runtime/syntax/java.vim

@@ -3,7 +3,7 @@
 " Maintainer:		Aliaksei Budavei <0x000c70 AT gmail DOT com>
 " Former Maintainer:	Claudio Fleiner <[email protected]>
 " Repository:		https://github.com/zzzyxwvut/java-vim.git
-" Last Change:		2025 Aug 07
+" Last Change:		2025 Aug 30
 
 " Please check ":help java.vim" for comments on some of the options
 " available.
@@ -447,6 +447,11 @@ if !exists("g:java_ignore_javadoc") && (s:with_html || s:with_markdown) && g:mai
 	unlet g:html_syntax_folding
       endif
 
+      if !empty(get(g:, 'markdown_fenced_languages', []))
+	let s:markdown_fenced_languages_copy = g:markdown_fenced_languages
+	unlet g:markdown_fenced_languages
+      endif
+
       syntax include @javaMarkdown syntax/markdown.vim
 
       try
@@ -464,6 +469,11 @@ if !exists("g:java_ignore_javadoc") && (s:with_html || s:with_markdown) && g:mai
     finally
       unlet! b:current_syntax
 
+      if exists("s:markdown_fenced_languages_copy")
+	let g:markdown_fenced_languages = s:markdown_fenced_languages_copy
+	unlet s:markdown_fenced_languages_copy
+      endif
+
       if exists("s:html_syntax_folding_copy")
 	let g:html_syntax_folding = s:html_syntax_folding_copy
 	unlet s:html_syntax_folding_copy