commit 81fcb67fb32a12414512b72e691a1bbbff9f8511
author Bram Moolenaar <Bram@vim.org> Tue Sep 01 21:21:24 2020 +0200
committer Bram Moolenaar <Bram@vim.org> Tue Sep 01 21:21:24 2020 +0200
tree 747185dbc68cd8766a53a8993570f05de992e711
parent 9c2b06637b32742cac11bfd66b1a4e84583c6c2e

patch 8.2.1561: using NULL pointers in fold code

Problem:    Using NULL pointers in fold code.
Solution:   Avoid using a NULL pointer. (Dominique Pellé, closes #6831,
            closes #6831)

src/fold.c

diff --git a/src/fold.c b/src/fold.c
index d95b46b..5c55b07 100644
--- a/src/fold.c
+++ b/src/fold.c
@@ -3059,7 +3059,7 @@
 }
 
 #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