commit fbd302ff38624abdec64980f4a19379d20a6e6c6
author Bram Moolenaar <Bram@vim.org> Sat Aug 08 18:23:46 2015 +0200
committer Bram Moolenaar <Bram@vim.org> Sat Aug 08 18:23:46 2015 +0200
tree f034dcc6fde785a494f884184f816e80357fe576
parent 204b93f95831454e6924acf30b16fd4bdfda0d14

patch 7.4.812
Problem:    Gcc sanitizer complains about using a NULL pointer to memmove().
Solution:   Only call memmove when there is something to move. (Vittorio
            Zecca)

src/memline.c

diff --git a/src/memline.c b/src/memline.c
index 8cd9b80..a1c07a9 100644
--- a/src/memline.c
+++ b/src/memline.c
@@ -3834,7 +3834,8 @@
 					(buf->b_ml.ml_stack_size + STACK_INCR));
 	if (newstack == NULL)
 	    return -1;
-	mch_memmove(newstack, buf->b_ml.ml_stack,
+	if (top > 0)
+	    mch_memmove(newstack, buf->b_ml.ml_stack,
 					     (size_t)top * sizeof(infoptr_T));
 	vim_free(buf->b_ml.ml_stack);
 	buf->b_ml.ml_stack = newstack;