1 files changed, 9 insertions, 5 deletions
diff --git a/Src/mem.c b/Src/mem.c
index 840bbb6e4..77e4375f0 100644
--- a/Src/mem.c
+++ b/Src/mem.c
@@ -1719,7 +1719,13 @@ calloc(MALLOC_ARG_T n, MALLOC_ARG_T size)
     if (!(l = n * size))
 	return (MALLOC_RET_T) m_high;
 
-    r = malloc(l);
+    /*
+     * use realloc() (with a NULL `p` argument it behaves exactly the same
+     * as malloc() does) to prevent an infinite loop caused by sibling-call
+     * optimizations (the malloc() call would otherwise be replaced by an
+     * unconditional branch back to line 1719 ad infinitum).
+     */
+    r = realloc(NULL, l);
 
     memset(r, 0, l);
 
@@ -1879,16 +1885,14 @@ bin_mem(char *name, char **argv, Options ops, int func)
 mod_export void
 zfree(void *p, UNUSED(int sz))
 {
-    if (p)
-	free(p);
+    free(p);
 }
 
 /**/
 mod_export void
 zsfree(char *p)
 {
-    if (p)
-	free(p);
+    free(p);
 }
 
 /**/