bug#19213: 25.0.50; [PATCH] * editfns.c (Ftranspose_regions): memmove instead of memcpy

[Fredrik Bergroth]

In one case, `memcpy' is used 4 times to transform [r1|mid|r2] into
[r2|mid|r1], but `dest' and `src' may overlap when copying the mid
interval, which is forbidden by `memcpy' and results in undefined
behavior. Instead use `memmove' like other cases do.
---
 src/editfns.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/editfns.c b/src/editfns.c
index 0a07886..82bd26d 100644
--- a/src/editfns.c
+++ b/src/editfns.c
@@ -4898,7 +4898,7 @@ Transposing beyond buffer boundaries is an error.  */)
          start2_addr = BYTE_POS_ADDR (start2_byte);
           memcpy (temp, start1_addr, len1_byte);
           memcpy (start1_addr, start2_addr, len2_byte);
-          memcpy (start1_addr + len2_byte, start1_addr + len1_byte, len_mid);
+          memmove (start1_addr + len2_byte, start1_addr + len1_byte, len_mid);
           memcpy (start1_addr + len2_byte + len_mid, temp, len1_byte);
          SAFE_FREE ();

--
1.9.1