vim-patch:7.4.710

Problem:    It is not possible to make spaces visibible in list mode.
Solution:   Add the "space" item to 'listchars'. (David Bürgin, issue 350)

https://github.com/vim/vim/releases/tag/v7-4-710

Closes #2485.

runtime/doc/options.txt

@@ -4450,9 +4450,13 @@ A jump table for the options with a short description can be found at |Q_op|.
 			fill the space that the tab normally occupies.
 			"tab:>-" will show a tab that takes four spaces as
 			">---".  When omitted, a tab is show as ^I.
+							*lcs-space*
+	  space:c	Character to show for a space.  When omitted, spaces
+			are left blank.
 							*lcs-trail*
 	  trail:c	Character to show for trailing spaces.  When omitted,
-			trailing spaces are blank.
+			trailing spaces are blank.  Overrides the "space"
+			setting for trailing spaces.
 							*lcs-extends*
 	  extends:c	Character to show in the last column, when 'wrap' is
 			off and the line continues beyond the right of the
@@ -4477,7 +4481,7 @@ A jump table for the options with a short description can be found at |Q_op|.
 	    :set lcs=tab:>-,eol:<,nbsp:%
 	    :set lcs=extends:>,precedes:<
 <	The "NonText" highlighting will be used for "eol", "extends" and
-	"precedes".  "SpecialKey" for "nbsp", "tab" and "trail".
+	"precedes".  "SpecialKey" for "nbsp", "space", "tab" and "trail".
 	|hl-NonText| |hl-SpecialKey|
 
 			*'lpl'* *'nolpl'* *'loadplugins'* *'noloadplugins'*

src/nvim/globals.h

@@ -998,6 +998,7 @@ EXTERN int lcs_eol INIT(= '$');
 EXTERN int lcs_ext INIT(= NUL);
 EXTERN int lcs_prec INIT(= NUL);
 EXTERN int lcs_nbsp INIT(= NUL);
+EXTERN int lcs_space INIT(= NUL);
 EXTERN int lcs_tab1 INIT(= NUL);
 EXTERN int lcs_tab2 INIT(= NUL);
 EXTERN int lcs_trail INIT(= NUL);

src/nvim/screen.c

@@ -3165,11 +3165,11 @@ win_line (
       }
       ++ptr;
 
-      /* 'list' : change char 160 to lcs_nbsp. */
-      if (wp->w_p_list && (c == 160
-                           || (mb_utf8 && mb_c == 160)
-                           ) && lcs_nbsp) {
-        c = lcs_nbsp;
+      // 'list': change char 160 to lcs_nbsp and space to lcs_space.
+      if (wp->w_p_list
+          && (((c == 160 || (mb_utf8 && mb_c == 160)) && lcs_nbsp)
+              || (c == ' ' && lcs_space && ptr <= line + trailcol))) {
+        c = (c == ' ') ? lcs_space : lcs_nbsp;
         if (area_attr == 0 && search_attr == 0) {
           n_attr = 1;
           extra_attr = hl_attr(HLF_8);

src/nvim/version.c

@@ -69,7 +69,7 @@ static char *features[] = {
 static int included_patches[] = {
   //712,
   //711,
-  //710,
+  710,
   //709,
   //708,
   //707,

test/functional/legacy/listchars_spec.lua

@@ -0,0 +1,96 @@
+-- Tests for 'listchars' display with 'list' and :list.
+
+local helpers = require('test.functional.helpers')
+local feed, insert, source = helpers.feed, helpers.insert, helpers.source
+local clear, execute, expect = helpers.clear, helpers.execute, helpers.expect
+
+describe("'listchars'", function()
+  before_each(clear)
+
+  it("works with 'list'", function()
+    source([[
+      function GetScreenCharsForLine(lnum)
+        return join(map(range(1, virtcol('$')), 'nr2char(screenchar(a:lnum, v:val))'), '')
+      endfunction
+      nnoremap <expr> GG ":call add(g:lines, GetScreenCharsForLine(".screenrow()."))\<CR>"
+    ]])
+
+    insert([[
+      start:
+      	aa	
+        bb	  
+         cccc	 
+      dd        ee  	
+       ]])
+
+    execute('let g:lines = []')
+
+    -- Set up 'listchars', switch on 'list', and use the "GG" mapping to record
+    -- what the buffer lines look like.
+    execute('set listchars+=tab:>-,space:.,trail:<')
+    execute('set list')
+    execute('/^start:/')
+    execute('normal! jzt')
+    feed('GG<cr>')
+    feed('GG<cr>')
+    feed('GG<cr>')
+    feed('GG<cr>')
+    feed('GGH')
+
+    -- Repeat without displaying "trail" spaces.
+    execute('set listchars-=trail:<')
+    feed('GG<cr>')
+    feed('GG<cr>')
+    feed('GG<cr>')
+    feed('GG<cr>')
+    feed('GG')
+
+    -- Delete the buffer contents and :put the collected lines.
+    execute('%d')
+    execute('put =g:lines', '1d')
+
+    -- Assert buffer contents.
+    expect([[
+      >-------aa>-----$
+      ..bb>---<<$
+      ...cccc><$
+      dd........ee<<>-$
+      <$
+      >-------aa>-----$
+      ..bb>---..$
+      ...cccc>.$
+      dd........ee..>-$
+      .$]])
+  end)
+
+  it('works with :list', function()
+    insert([[
+      start:
+        fff	  
+      	gg	
+           h	
+      iii    	  ]])
+
+    -- Set up 'listchars', switch 'list' *off* (:list must show the 'listchars'
+    -- even when 'list' is off), then run :list and collect the output.
+    execute('set listchars+=tab:>-,space:.,trail:<')
+    execute('set nolist')
+    execute('/^start:/')
+    execute('redir! => g:lines')
+    execute('+1,$list')
+    execute('redir END')
+
+    -- Delete the buffer contents and :put the collected lines.
+    execute('%d')
+    execute('put =g:lines', '1d')
+
+    -- Assert buffer contents.
+    expect([[
+      
+      
+      ..fff>--<<$
+      >-------gg>-----$
+      .....h>-$
+      iii<<<<><<$]])
+  end)
+end)