[PATCH 1/2] add MOVE_ARRAY

["René Scharfe" <l.s.r@web.de>]

Add MOVE_ARRAY to complement COPY_ARRAY, which was added in 60566cbb.
It provides the same convenience, safety and support for NULL pointers
as representations of empty arrays, just as a wrapper for memmove(3)
instead of memcpy(3).

Inspired-by: Martin Liska <mliska@suse.cz>
Signed-off-by: Rene Scharfe <l.s.r@web.de>
---
 git-compat-util.h | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/git-compat-util.h b/git-compat-util.h
index 8a4a3f85e7..3266a71fb4 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -812,6 +812,14 @@ static inline void copy_array(void *dst, const void *src, size_t n, size_t size)
 		memcpy(dst, src, st_mult(size, n));
 }
 
+#define MOVE_ARRAY(dst, src, n) move_array((dst), (src), (n), sizeof(*(dst)) + \
+	BUILD_ASSERT_OR_ZERO(sizeof(*(dst)) == sizeof(*(src))))
+static inline void move_array(void *dst, const void *src, size_t n, size_t size)
+{
+	if (n)
+		memmove(dst, src, st_mult(size, n));
+}
+
 /*
  * These functions help you allocate structs with flex arrays, and copy
  * the data directly into the array. For example, if you had:
-- 
2.12.2