patch 9.1.0084: Visual hl wrong when it ends before multibyte 'showbreak'

Problem:  Visual hl wrong when it ends before multibyte 'showbreak'.
          (lacygoil)
Solution: Use vcol_sbr instead of adding n_extra.
          (zeertzjq)

fixes: #11272
closes: #13996

Signed-off-by: zeertzjq <zeertzjq@outlook.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

src/drawline.c

@@ -589,7 +589,7 @@ handle_showbreak_and_filler(win_T *wp, winlinevars_T *wlv)
 	// Correct end of highlighted area for 'showbreak',
 	// required when 'linebreak' is also set.
 	if (wlv->tocol == wlv->vcol)
-	    wlv->tocol += wlv->n_extra;
+	    wlv->tocol = wlv->vcol_sbr;
 	// combine 'showbreak' with 'wincolor'
 	wlv->char_attr = hl_combine_attr(wlv->win_attr, HL_ATTR(HLF_AT));
 #  ifdef FEAT_SYN_HL

src/testdir/dumps/Test_visual_ends_before_showbreak.dump

@@ -0,0 +1,6 @@
+|x+0&#ffffff0@4| @69
+|↪+0#4040ff13&| |y+0#0000001#a8a8a8255@68> +0#0000000#ffffff0| +0#0000001#a8a8a8255@2
+|↪+0#4040ff13#ffffff0| |z+0#0000000&@3| @68
+|~+0#4040ff13&| @73
+|~| @73
+|-+2#0000000&@1| |V|I|S|U|A|L| |-@1| +0&&@34|7|0| @7|1|,|7|6|-|1|4|7| @5|A|l@1| 

src/testdir/test_listlbr_utf8.vim

@@ -9,6 +9,7 @@ CheckFeature conceal
 CheckFeature signs
 
 source view_util.vim
+source screendump.vim
 
 func s:screen_lines(lnum, width) abort
   return ScreenLines(a:lnum, a:width)
@@ -358,4 +359,24 @@ func Test_unprintable_char_on_wrap_column()
   call s:close_windows()
 endfunc
 
+" Test that Visual selection is drawn correctly when 'linebreak' is set and
+" selection ends before multibyte 'showbreak'.
+func Test_visual_ends_before_showbreak()
+  CheckScreendump
+
+  let lines =<< trim END
+      vim9script
+      &wrap = true
+      &linebreak = true
+      &showbreak = '↪ '
+      ['xxxxx ' .. 'y'->repeat(&columns - 6) .. ' zzzz']->setline(1)
+      normal! wvel
+  END
+  call writefile(lines, 'XvisualEndsBeforeShowbreak', 'D')
+  let buf = RunVimInTerminal('-S XvisualEndsBeforeShowbreak', #{rows: 6})
+  call VerifyScreenDump(buf, 'Test_visual_ends_before_showbreak', {})
+
+  call StopVimInTerminal(buf)
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab

src/version.c

@@ -704,6 +704,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    84,
 /**/
     83,
 /**/