diff --git a/tmp/c-old/src/buffer/sds.c b/tmp/c-old/src/buffer/sds.c
index e1fdfb63..659509eb 100644
--- a/tmp/c-old/src/buffer/sds.c
+++ b/tmp/c-old/src/buffer/sds.c
@@ -224,7 +224,7 @@ sds sdsMakeRoomFor(sds s, size_t addlen)
 {
 	void *sh, *newsh;
 	size_t avail = sdsavail(s);
-	size_t len, newlen;
+	size_t len, newlen, reqlen;
 	char type, oldtype = s[-1] & SDS_TYPE_MASK;
 	int hdrlen;
 
@@ -234,7 +234,8 @@ sds sdsMakeRoomFor(sds s, size_t addlen)
 
 	len = sdslen(s);
 	sh = (char *)s - sdsHdrSize(oldtype);
-	newlen = (len + addlen);
+	reqlen = newlen = (len + addlen);
+	assert(newlen > len);   /* Catch size_t overflow */
 	if (newlen < SDS_MAX_PREALLOC)
 		newlen *= 2;
 	else
@@ -249,6 +250,7 @@ sds sdsMakeRoomFor(sds s, size_t addlen)
 		type = SDS_TYPE_8;
 
 	hdrlen = sdsHdrSize(type);
+	assert(hdrlen + newlen + 1 > reqlen);  /* Catch size_t overflow */
 	if (oldtype == type)
 	{
 		newsh = s_realloc(sh, hdrlen + newlen + 1);