vim-patch:8.1.0174: after paging up and down fold line is wrong

Problem:    After paging up and down fold line is wrong.
Solution:   Correct the computation of w_topline and w_botline. (Hirohito
            Higashi)
https://github.com/vim/vim/commit/907dad72ef9d29422352fb74ba156e7085a3fc71

1 files changed, 12 insertions, 10 deletions

diff --git a/src/nvim/move.c b/src/nvim/move.c
index 41859a489f..4261a52054 100644
--- a/src/nvim/move.c
+++ b/src/nvim/move.c
@@ -1884,16 +1884,18 @@ int onepage(int dir, long count)
   }
   curwin->w_valid &= ~(VALID_WCOL|VALID_WROW|VALID_VIRTCOL);
 
-  /*
-   * Avoid the screen jumping up and down when 'scrolloff' is non-zero.
-   * But make sure we scroll at least one line (happens with mix of long
-   * wrapping lines and non-wrapping line).
-   */
-  if (retval == OK && dir == FORWARD && check_top_offset()) {
-    scroll_cursor_top(1, false);
-    if (curwin->w_topline <= old_topline
-        && old_topline < curbuf->b_ml.ml_line_count) {
-      curwin->w_topline = old_topline + 1;
+  if (retval == OK && dir == FORWARD) {
+    // Avoid the screen jumping up and down when 'scrolloff' is non-zero.
+    // But make sure we scroll at least one line (happens with mix of long
+    // wrapping lines and non-wrapping line).
+    if (check_top_offset()) {
+      scroll_cursor_top(1, false);
+      if (curwin->w_topline <= old_topline
+          && old_topline < curbuf->b_ml.ml_line_count) {
+        curwin->w_topline = old_topline + 1;
+        (void)hasFolding(curwin->w_topline, &curwin->w_topline, NULL);
+      }
+    } else if (curwin->w_botline > curbuf->b_ml.ml_line_count) {
       (void)hasFolding(curwin->w_topline, &curwin->w_topline, NULL);
     }
   }