patch 8.1.0280: 'incsearch' highlighting does not work for ":g!/"

Problem:    'incsearch' highlighting does not work for ":g!/".
Solution:   Skip the exclamation mark. (Hirohito Higashi)

src/ex_getln.c

@@ -298,6 +298,13 @@ do_incsearch_highlighting(int firstc, incsearch_state_T *is_state,
 			    || STRNCMP(cmd, "global", p - cmd) == 0
 			    || STRNCMP(cmd, "vglobal", p - cmd) == 0))
 		{
+		    // Check for "global!/".
+		    if (*cmd == 'g' && *p == '!')
+		    {
+			p++;
+			if (*skipwhite(p) == NUL)
+			    return FALSE;
+		    }
 		    p = skipwhite(p);
 		    delim = *p++;
 		    end = skip_regexp(p, delim, p_magic, NULL);

src/testdir/test_search.vim

@@ -399,6 +399,14 @@ func Test_search_cmdline3g()
   undo
   call feedkeys(":global/the\<c-l>/d\<cr>", 'tx')
   call assert_equal('  3 the theother', getline(2))
+  undo
+  call feedkeys(":g!/the\<c-l>/d\<cr>", 'tx')
+  call assert_equal(1, line('$'))
+  call assert_equal('  2 the~e', getline(1))
+  undo
+  call feedkeys(":global!/the\<c-l>/d\<cr>", 'tx')
+  call assert_equal(1, line('$'))
+  call assert_equal('  2 the~e', getline(1))
 
   call Incsearch_cleanup()
 endfunc

src/version.c

@@ -794,6 +794,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    280,
 /**/
     279,
 /**/