patch 8.1.0168: output of :marks is too short with multi-byte chars

Problem:    Output of :marks is too short with multi-byte chars. (Tony
            Mechelynck)
Solution:   Get more bytes from the text line.

src/mark.c

@@ -686,10 +686,11 @@ mark_line(pos_T *mp, int lead_len)
 
     if (mp->lnum == 0 || mp->lnum > curbuf->b_ml.ml_line_count)
 	return vim_strsave((char_u *)"-invalid-");
-    s = vim_strnsave(skipwhite(ml_get(mp->lnum)), (int)Columns);
+    // Allow for up to 5 bytes per character.
+    s = vim_strnsave(skipwhite(ml_get(mp->lnum)), (int)Columns * 5);
     if (s == NULL)
 	return NULL;
-    /* Truncate the line to fit it in the window */
+    // Truncate the line to fit it in the window.
     len = 0;
     for (p = s; *p != NUL; MB_PTR_ADV(p))
     {

src/testdir/test_marks.vim

@@ -80,7 +80,7 @@ func Test_marks_cmd()
   w!
 
   b Xone
-  let a=split(execute('marks'), "\n")
+  let a = split(execute('marks'), "\n")
   call assert_equal(9, len(a))
   call assert_equal('mark line  col file/text', a[0])
   call assert_equal(" '      2    0 bbb", a[1])
@@ -93,7 +93,7 @@ func Test_marks_cmd()
   call assert_equal(' .      2    0 bbb', a[8])
 
   b Xtwo
-  let a=split(execute('marks'), "\n")
+  let a = split(execute('marks'), "\n")
   call assert_equal(9, len(a))
   call assert_equal('mark line  col file/text', a[0])
   call assert_equal(" '      1    0 ccc", a[1])
@@ -107,7 +107,7 @@ func Test_marks_cmd()
 
   b Xone
   delmarks aB
-  let a=split(execute('marks aBcD'), "\n")
+  let a = split(execute('marks aBcD'), "\n")
   call assert_equal(2, len(a))
   call assert_equal('mark line  col file/text', a[0])
   call assert_equal(' D      2    0 Xtwo', a[1])
@@ -120,3 +120,22 @@ func Test_marks_cmd()
   call delete('Xtwo')
   %bwipe
 endfunc
+
+func Test_marks_cmd_multibyte()
+  if !has('multi_byte')
+    return
+  endif
+  new Xone
+  call setline(1, ['ááááááááááááááááááááááááááááááááááááááááááááááááááááááááááááááááááááááááááááááááá'])
+  norm! ma
+
+  let a = split(execute('marks a'), "\n")
+  call assert_equal(2, len(a))
+  let expected = ' a      1    0 '
+  while strwidth(expected) < &columns - 1
+    let expected .= 'á'
+  endwhile
+  call assert_equal(expected, a[1])
+
+  bwipe!
+endfunc

src/version.c

@@ -789,6 +789,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    168,
 /**/
     167,
 /**/