# HG changeset patch
# User Bram Moolenaar <Bram@vim.org>
# Date 1598988604 -7200
# Node ID 67d3826948adc07481bb0066139c6f63b3958cb5
# Parent  b692415fc88b8da25bc7da4da2fa8335fe0a27d2
patch 8.2.1561: using NULL pointers in fold code

Commit: https://github.com/vim/vim/commit/81fcb67fb32a12414512b72e691a1bbbff9f8511
Author: Bram Moolenaar <Bram@vim.org>
Date:   Tue Sep 1 21:21:24 2020 +0200

    patch 8.2.1561: using NULL pointers in fold code

    Problem:    Using NULL pointers in fold code.
    Solution:   Avoid using a NULL pointer. (Dominique Pell?, closes https://github.com/vim/vim/issues/6831,
                closes #6831)

diff --git a/src/fold.c b/src/fold.c
--- a/src/fold.c
+++ b/src/fold.c
@@ -3059,7 +3059,7 @@ truncate_fold(fold_T *fp, linenr_T end)
 }
 
 #define fold_end(fp) ((fp)->fd_top + (fp)->fd_len - 1)
-#define valid_fold(fp, gap) ((fp) < ((fold_T *)(gap)->ga_data + (gap)->ga_len))
+#define valid_fold(fp, gap) ((gap)->ga_len > 0 && (fp) < ((fold_T *)(gap)->ga_data + (gap)->ga_len))
 #define fold_index(fp, gap) ((size_t)(fp - ((fold_T *)(gap)->ga_data)))
 
     void
diff --git a/src/version.c b/src/version.c
--- a/src/version.c
+++ b/src/version.c
@@ -755,6 +755,8 @@ static char *(features[]) =
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1561,
+/**/
     1560,
 /**/
     1559,