patch 9.0.0414: matchstr() still does not match column offset

Problem:    matchstr() still does not match column offset when done after a
            text search.
Solution:   Only use the line number for a multi-line search.  Fix the test.
            (closes #10938)

Author: brammool

src/regexp_bt.c

@@ -3441,11 +3441,13 @@ regmatch(
 	  case RE_VCOL:
 	    {
 		win_T	    *wp = rex.reg_win == NULL ? curwin : rex.reg_win;
-		linenr_T    lnum = rex.reg_firstlnum + rex.lnum;
-		long_u	    vcol = 0;
+		linenr_T    lnum = REG_MULTI ? rex.reg_firstlnum + rex.lnum : 1;
+		long_u	    vcol;
 
-		if (lnum >= 0 && lnum <= wp->w_buffer->b_ml.ml_line_count)
-		    vcol = (long_u)win_linetabsize(wp, lnum, rex.line,
+		if (REG_MULTI && (lnum <= 0
+				   || lnum > wp->w_buffer->b_ml.ml_line_count))
+		    lnum = 1;
+		vcol = (long_u)win_linetabsize(wp, lnum, rex.line,
 					      (colnr_T)(rex.input - rex.line));
 		if (!re_num_cmp(vcol + 1, scan))
 		    status = RA_NOMATCH;

src/regexp_nfa.c

@@ -6775,12 +6775,14 @@ nfa_regmatch(
 		    }
 		    if (!result)
 		    {
-			linenr_T    lnum = rex.reg_firstlnum + rex.lnum;
-			long_u	    vcol = 0;
-
-			if (lnum >= 0
-				   && lnum <= wp->w_buffer->b_ml.ml_line_count)
-			    vcol = (long_u)win_linetabsize(wp, lnum,
+			linenr_T    lnum = REG_MULTI
+					    ? rex.reg_firstlnum + rex.lnum : 1;
+			long_u	    vcol;
+
+			if (REG_MULTI && (lnum <= 0
+				   || lnum > wp->w_buffer->b_ml.ml_line_count))
+			    lnum = 1;
+			vcol = (long_u)win_linetabsize(wp, lnum,
 								rex.line, col);
 			result = nfa_re_num_cmp(t->state->val, op, vcol + 1);
 		    }

src/testdir/test_regexp_latin.vim

@@ -1145,7 +1145,13 @@ def Test_compare_columns()
 enddef
 
 def Test_compare_column_matchstr()
+  # do some search in text to set the line number, it should be ignored in
+  # matchstr().
   enew
+  setline(1, ['one', 'two', 'three'])
+  :3 
+  :/ee
+  bwipe!
   set re=1
   call assert_equal('aaa', matchstr('aaaaaaaaaaaaaaaaaaaa', '.*\%<5v'))
   set re=2

src/version.c

@@ -703,6 +703,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    414,
 /**/
     413,
 /**/