Improvement: gqq autowrap leading :: definition as &l:comments (#1279)

doc/vimwiki.txt

@@ -4020,6 +4020,11 @@ master is retained as a legacy mirror of the dev branch.
 
 This is somewhat experimental, and will probably be refined over time.
 
+New:~
+    * Issue #1279: Fix/Improvement: When re-wrap a long line in a definition
+      by 'gq' it should insert ':: ' at the new line 
+    
+
 2023.04.04~
 
 Fixed:~

ftplugin/vimwiki.vim

@@ -149,6 +149,10 @@ for bullet in vimwiki#vars#get_syntaxlocal('bullet_types')
   " list
   let comments .= ',fb:' . bullet
 endfor
+" Add :: for vimwiki default syntax (#1279)
+if 'default' ==# vimwiki#vars#get_wikilocal('syntax')
+  let comments .= ',b:::'
+endif
 let &l:comments = comments
 
 " Set Format Options: (:h fo-table)

test/issue_1279_gq_wrap_definition.vader

@@ -0,0 +1,15 @@
+# Non regression tests for issue: #1279
+# Fix/Improvement: When re-wrap a long line in a definition by 'gq' it should insert ':: ' at the new line
+
+
+Given vimwiki (Dummy heading):
+  :: aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa
+
+Do (gqq):
+  gqq
+
+Expect (Heading6):
+  :: aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa
+  :: aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa
+  :: aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa
+  :: aaa aaa aaa