vim-patch:8.1.1890: ml_get error when deleting fold marker

Problem:    Ml_get error when deleting fold marker.
Solution:   Check that the line number is not below the last line.  Adjust the
            fold when deleting the empty line.  (Christian Brabandt,
            closes vim/vim#4834)
https://github.com/vim/vim/commit/9a4a8c4d5993c6371486c895a515c2ad351e9aaa

3 files changed, 36 insertions, 11 deletions

diff --git a/src/nvim/fold.c b/src/nvim/fold.c
index ad0bfe29e2..5ce953e626 100644
--- a/src/nvim/fold.c
+++ b/src/nvim/fold.c
@@ -1645,19 +1645,22 @@ deleteFoldMarkers(
                 foldendmarkerlen);
 }
 
-/* foldDelMarker() {{{2 */
-/*
- * Delete marker "marker[markerlen]" at the end of line "lnum".
- * Delete 'commentstring' if it matches.
- * If the marker is not found, there is no error message.  Could a missing
- * close-marker.
- */
+// foldDelMarker() {{{2
+//
+// Delete marker "marker[markerlen]" at the end of line "lnum".
+// Delete 'commentstring' if it matches.
+// If the marker is not found, there is no error message.  Could be a missing
+// close-marker.
 static void foldDelMarker(linenr_T lnum, char_u *marker, size_t markerlen)
 {
   char_u      *newline;
   char_u      *cms = curbuf->b_p_cms;
   char_u      *cms2;
 
+  // end marker may be missing and fold extends below the last line
+  if (lnum > curbuf->b_ml.ml_line_count) {
+    return;
+  }
   char_u *line = ml_get(lnum);
   for (char_u *p = line; *p != NUL; ++p) {
     if (STRNCMP(p, marker, markerlen) != 0) {
@@ -2426,15 +2429,18 @@ static linenr_T foldUpdateIEMSRecurse(
    * lvl >= level: fold continues below "bot"
    */
 
-  /* Current fold at least extends until lnum. */
+  // Current fold at least extends until lnum.
   if (fp->fd_len < flp->lnum - fp->fd_top) {
     fp->fd_len = flp->lnum - fp->fd_top;
     fp->fd_small = kNone;
     fold_changed = true;
+  } else if (fp->fd_top + fp->fd_len > linecount) {
+    // running into the end of the buffer (deleted last line)
+    fp->fd_len = linecount - fp->fd_top + 1;
   }
 
-  /* Delete contained folds from the end of the last one found until where
-   * we stopped looking. */
+  // Delete contained folds from the end of the last one found until where
+  // we stopped looking.
   foldRemove(&fp->fd_nested, startlnum2 - fp->fd_top,
       flp->lnum - 1 - fp->fd_top);
 
diff --git a/src/nvim/normal.c b/src/nvim/normal.c
index 73841cf449..bfd91e688e 100644
--- a/src/nvim/normal.c
+++ b/src/nvim/normal.c
@@ -7827,13 +7827,15 @@ static void nv_put_opt(cmdarg_T *cap, bool fix_indent)
       // 'virtualedit' and past the end of the line, we use the 'c' operator in
       // do_put(), which requires the visual selection to still be active.
       if (!VIsual_active || VIsual_mode == 'V' || regname != '.') {
-        // Now delete the selected text.
+        // Now delete the selected text. Avoid messages here.
         cap->cmdchar = 'd';
         cap->nchar = NUL;
         cap->oap->regname = NUL;
+        msg_silent++;
         nv_operator(cap);
         do_pending_operator(cap, 0, false);
         empty = (curbuf->b_ml.ml_flags & ML_EMPTY);
+        msg_silent--;
 
         // delete PUT_LINE_BACKWARD;
         cap->oap->regname = regname;
@@ -7882,6 +7884,7 @@ static void nv_put_opt(cmdarg_T *cap, bool fix_indent)
      * line that needs to be deleted now. */
     if (empty && *ml_get(curbuf->b_ml.ml_line_count) == NUL) {
       ml_delete(curbuf->b_ml.ml_line_count, true);
+      deleted_lines(curbuf->b_ml.ml_line_count + 1, 1);
 
       /* If the cursor was in that line, move it to the end of the last
        * line. */
diff --git a/src/nvim/testdir/test_fold.vim b/src/nvim/testdir/test_fold.vim
index df3d691d85..4036eae678 100644
--- a/src/nvim/testdir/test_fold.vim
+++ b/src/nvim/testdir/test_fold.vim
@@ -740,3 +740,19 @@ func Test_folds_marker_in_comment2()
   set foldmethod&
   bwipe!
 endfunc
+
+func Test_fold_delete_with_marker()
+  new
+  call setline(1, ['func Func() {{{1', 'endfunc'])
+  1,2yank
+  new
+  set fdm=marker
+  call setline(1, 'x')
+  normal! Vp
+  normal! zd
+  call assert_equal(['func Func() ', 'endfunc'], getline(1, '$'))
+
+  set fdm&
+  bwipe!
+  bwipe!
+endfunc