Fix realloc(3) when chk_malloc debugging is on.

The tests for a NULL pointer and size 0 were the wrong way round.

From Intel's patch 9cae4f2ffc4778ed82be04711d8775a84092d4e2.

Change-Id: I118aff3358aa5f34126d74bfaa43f6e2f1a89055

1 files changed, 6 insertions, 4 deletions

diff --git a/libc/bionic/malloc_debug_check.cpp b/libc/bionic/malloc_debug_check.cpp
index 4190a1d..5ad3486 100644
--- a/libc/bionic/malloc_debug_check.cpp
+++ b/libc/bionic/malloc_debug_check.cpp
@@ -406,14 +406,16 @@ extern "C" void chk_free(void *ptr) {
 extern "C" void *chk_realloc(void *ptr, size_t size) {
 //  log_message("%s: %s\n", __FILE__, __FUNCTION__);
 
+    if (!ptr) {
+        return chk_malloc(size);
+    }
+
+#ifdef REALLOC_ZERO_BYTES_FREE
     if (!size) {
         chk_free(ptr);
         return NULL;
     }
-
-    if (!ptr) {
-        return chk_malloc(size);
-    }
+#endif
 
     hdr_t* hdr = meta(ptr);