patch 8.1.0449: when 'rnu' is set folded lines are not displayed correctly

Problem:    When 'rnu' is set folded lines are not displayed correctly.
            (Vitaly Yashin)
Solution:   When only redrawing line numbers do draw folded lines.
            (closes #3484)

src/screen.c

@@ -2176,6 +2176,13 @@ win_update(win_T *wp)
 	    {
 		// 'relativenumber' set: The text doesn't need to be drawn, but
 		// the number column nearly always does.
+		fold_count = foldedCount(wp, lnum, &win_foldinfo);
+		if (fold_count != 0)
+		{
+		    fold_line(wp, fold_count, &win_foldinfo, lnum, row);
+		    --fold_count;
+		}
+		else
 		    (void)win_line(wp, lnum, srow, wp->w_height, TRUE, TRUE);
 	    }
 
@@ -3315,8 +3322,8 @@ win_line(
 	    has_spell = TRUE;
 	    extra_check = TRUE;
 
-	    /* Get the start of the next line, so that words that wrap to the next
+	    /* Get the start of the next line, so that words that wrap to the
-	     * line are found too: "et<line-break>al.".
+	     * next line are found too: "et<line-break>al.".
 	     * Trick: skip a few chars for C/shell/Vim comments */
 	    nextline[SPWORDLEN] = NUL;
 	    if (lnum < wp->w_buffer->b_ml.ml_line_count)
@@ -3325,8 +3332,8 @@ win_line(
 		spell_cat_line(nextline + SPWORDLEN, line, SPWORDLEN);
 	    }
 
-	    /* When a word wrapped from the previous line the start of the current
+	    /* When a word wrapped from the previous line the start of the
-	     * line is valid. */
+	     * current line is valid. */
 	    if (lnum == checked_lnum)
 		cur_checked_col = checked_col;
 	    checked_lnum = 0;

src/testdir/dumps/Test_folds_with_rnu_01.dump

@@ -0,0 +1,20 @@
+|++0#0000e05#a8a8a8255| @2|0| >+|-@1| @1|2| |l|i|n|e|s|:| |-@54
+|+| @2|1| |+|-@1| @1|2| |l|i|n|e|s|:| |-@54
+| @1|~+0#4040ff13#ffffff0| @71
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @71
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @71
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @71
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @71
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @71
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @71
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @71
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @71
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @71
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @71
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @71
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @71
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @71
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @71
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @71
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @71
+| +0#0000000&@56|1|,|1| @10|A|l@1| 

src/testdir/dumps/Test_folds_with_rnu_02.dump

@@ -0,0 +1,20 @@
+|++0#0000e05#a8a8a8255| @2|1| |+|-@1| @1|2| |l|i|n|e|s|:| |-@54
+|+| @2|0| >+|-@1| @1|2| |l|i|n|e|s|:| |-@54
+| @1|~+0#4040ff13#ffffff0| @71
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @71
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @71
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @71
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @71
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @71
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @71
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @71
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @71
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @71
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @71
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @71
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @71
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @71
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @71
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @71
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @71
+| +0#0000000&@56|3|,|1| @10|A|l@1| 

src/testdir/test_fold.vim

@@ -1,6 +1,7 @@
 " Test for folding
 
 source view_util.vim
+source screendump.vim
 
 func PrepIndent(arg)
   return [a:arg] + repeat(["\t".a:arg], 5)
@@ -674,3 +675,23 @@ func Test_fold_last_line_with_pagedown()
   set fdm&
   enew!
 endfunc
+
+func Test_folds_with_rnu()
+  if !CanRunVimInTerminal()
+    return
+  endif
+
+  call writefile([
+	\ 'set fdm=marker rnu foldcolumn=2',
+	\ 'call setline(1, ["{{{1", "nline 1", "{{{1", "line 2"])',
+	\ ], 'Xtest_folds_with_rnu')
+  let buf = RunVimInTerminal('-S Xtest_folds_with_rnu', {})
+
+  call VerifyScreenDump(buf, 'Test_folds_with_rnu_01', {})
+  call term_sendkeys(buf, "j")
+  call VerifyScreenDump(buf, 'Test_folds_with_rnu_02', {})
+
+  " clean up
+  call StopVimInTerminal(buf)
+  call delete('Xtest_folds_with_rnu')
+endfunc

src/version.c

@@ -792,6 +792,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    449,
 /**/
     448,
 /**/