runtime(comment): add gC mapping to (un)comment rest of line

fixes: #15727
closes: #15737

Signed-off-by: Konfekt <Konfekt@users.noreply.github.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

runtime/pack/dist/opt/comment/autoload/comment.vim

@@ -1,7 +1,7 @@
 vim9script
 
 # Maintainer: Maxim Kim <habamax@gmail.com>
-# Last Update: 2024-04-26
+# Last Update: 2024-09-24
 #
 # Toggle comments
 # Usage:
@@ -10,6 +10,7 @@ vim9script
 #       nnoremap <silent> <expr> gc comment.Toggle()
 #       xnoremap <silent> <expr> gc comment.Toggle()
 #       nnoremap <silent> <expr> gcc comment.Toggle() .. '_'
+#       nnoremap <silent> <expr> gC  comment.Toggle() .. '$'
 export def Toggle(...args: list<string>): string
     if len(args) == 0
         &opfunc = matchstr(expand('<stack>'), '[^. ]*\ze[')
@@ -19,6 +20,19 @@ export def Toggle(...args: list<string>): string
     var cms = substitute(substitute(&cms, '\S\zs%s\s*', ' %s', ''), '%s\ze\S', '%s ', '')
     var [lnum1, lnum2] = [line("'["), line("']")]
     var cms_l = split(escape(cms, '*.'), '\s*%s\s*')
+
+    var first_col = indent(lnum1)
+    var start_col = getpos("'[")[2]
+    if len(cms_l) == 1 && lnum1 == lnum2 && first_col < start_col
+        var line_start = getline(lnum1)[0 : max(0, start_col - 2)]
+        var line_end = getline(lnum1)[start_col - 1 : -1]
+        line_end = line_end =~# $'^\s*{cms_l[0]}' ?
+                    \ substitute(line_end, $'^\s*\zs{cms_l[0]}', '', '') :
+                    \ printf(substitute(cms, '%s\@!', '%%', 'g'), line_end)
+        setline(lnum1, line_start .. line_end)
+        return ''
+    endif
+
     if len(cms_l) == 0 | return '' | endif
     if len(cms_l) == 1 | call add(cms_l, '') | endif
     var comment = 0

runtime/pack/dist/opt/comment/doc/comment.txt

@@ -1,4 +1,4 @@
-*comment.txt*   For Vim version 9.1.  Last change:  2024 Jun 04
+*comment.txt*   For Vim version 9.1.  Last change:  2024 Sep 29
 
 
 		  VIM REFERENCE MANUAL
@@ -12,17 +12,26 @@ See |comment-install| on how to activate this package.
 The comment.vim package, allows to toggle comments for a single line, a range
 of lines or a selected text object.  It defines the following mappings:
 
-							*gcc*
-gcc		to comment/uncomment current line
 							*o_gc*
 gc{motion}	to toggle comments for the selected motion
-							*gcip*
-gcip		to comment/uncomment current paragraph
-							*gcG*
-gcG		to comment/uncomment from current line till the end of a buffer
 							*v_gc*
 {Visual}gc	to comment/uncomment the highlighted lines.
 
+Since gc operates on a motion, it can be used with any motion, for example _
+to comment the current line, or ip to comment the current paragraph.
+A default mapping `gcc` to `gc_` is defined:
+							*gcc*
+gcc		to comment/uncomment current line
+
+To comment the rest of the line by  `gC`  whenever the filetype plugin
+supports it (that is, whenever the comment marker precedes the code) and fall
+back to `gcc` otherwise, add the following mapping to your vimrc: >
+
+	nnoremap <silent> <expr> gC comment.Toggle() .. '$'
+<
+Note: using `gC` may not always result in valid comment markers depending on
+the language used.
+
 This plugin uses the buffer-local 'commentstring' option value to add or remove
 comment markers to the selected lines.  Whether it will comment or un-comment
 depends on the first line of the range of lines to act upon.  When it matches

runtime/pack/dist/opt/comment/doc/tags

@@ -1,8 +1,6 @@
 b:comment_first_col	comment.txt	/*b:comment_first_col*
 comment.txt	comment.txt	/*comment.txt*
 g:comment_first_col	comment.txt	/*g:comment_first_col*
-gcG	comment.txt	/*gcG*
 gcc	comment.txt	/*gcc*
-gcip	comment.txt	/*gcip*
 o_gc	comment.txt	/*o_gc*
 v_gc	comment.txt	/*v_gc*