vim-patch:8.2.4062: match highlighting of tab too short

Problem:    Match highlighting of tab too short.
Solution:   Do not stop match highlighting if on a Tab. (Christian Brabandt,
            closes vim/vim#9507, closes vim/vim#9500)

0bbca540f7

Co-authored-by: Bram Moolenaar <Bram@vim.org>

src/nvim/drawline.c

@@ -1844,9 +1844,10 @@ int win_line(win_T *wp, linenr_T lnum, int startrow, int endrow, bool nochange,
               n_extra = 0;
             }
           }
-          if (on_last_col) {
+          if (on_last_col && c != TAB) {
             // Do not continue search/match highlighting over the
-            // line break.
+            // line break, but for TABs the highlighting should
+            // include the complete width of the character
             search_attr = 0;
           }
 

src/nvim/testdir/test_match.vim

@@ -421,4 +421,22 @@ func Test_matchdelete_redraw()
   bw!
 endfunc
 
+func Test_match_tab_with_linebreak()
+  CheckRunVimInTerminal
+
+  let lines =<< trim END
+    set linebreak
+    call setline(1, "\tix")
+    call matchadd('ErrorMsg', '\t')
+  END
+  call writefile(lines, 'XscriptMatchTabLinebreak')
+  let buf = RunVimInTerminal('-S XscriptMatchTabLinebreak', #{rows: 10})
+  call TermWait(buf)
+  call VerifyScreenDump(buf, 'Test_match_tab_linebreak', {})
+
+  call StopVimInTerminal(buf)
+  call delete('XscriptMatchTabLinebreak')
+endfunc
+
+
 " vim: shiftwidth=2 sts=2 expandtab