memalign(): verify properly that alignment is a power of two

src/memalign.c

@@ -54,7 +54,8 @@ void *memalign(size_t alignment, size_t size) {
     DEFAULT_RB_T *encapsulated_rb;
     raw_block_header_t *raw_block;
 
-    assert((alignment & 1) == 0);
+    /* Verify that alignment is a power of two */
+    assert((alignment && !(alignment & (alignment - 1))) != 0);
 
     memptr = NULL;