* src/alloc.c (resize_string_data): Adjust string bytes (Bug#42540)

diff --git a/src/alloc.c b/src/alloc.c
index 5b9c6e4eb1f96203267e6e4c5e5f7ec7db95bdbc..f203061161b89a1f2855210cd2eab383e81d0970 100644 (file)
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -1947,6 +1947,9 @@ resize_string_data (Lisp_Object string, ptrdiff_t cidx_byte,
       /* No need to reallocate, as the size change falls within the
         alignment slop.  */
       XSTRING (string)->u.s.size_byte = new_nbytes;
+#ifdef GC_CHECK_STRING_BYTES
+      SDATA_NBYTES (old_sdata) = new_nbytes;
+#endif
       new_charaddr = data + cidx_byte;
       memmove (new_charaddr + new_clen, new_charaddr + clen,
               nbytes - (cidx_byte + (clen - 1)));