From f336936309e2803ca6b82612240d36ba45b017cf Mon Sep 17 00:00:00 2001
From: shinyquagsire23 <mtinc2@gmail.com>
Date: Fri, 5 Aug 2016 12:10:19 -0700
Subject: [PATCH] Improve overall handling of realloc

---
 crt/memory.c | 26 ++++++++++++++++++--------
 1 file changed, 18 insertions(+), 8 deletions(-)

diff --git a/crt/memory.c b/crt/memory.c
index 056df20..6cd0b5b 100644
--- a/crt/memory.c
+++ b/crt/memory.c
@@ -20,15 +20,30 @@ __wrap_free(void *ptr) {
    }
 }
 
+size_t
+__wrap_malloc_usable_size(void *ptr) {
+   return MEMGetSizeForMBlockExpHeap(ptr);
+}
+
 void *
 __wrap_realloc(void *ptr, size_t size) {
+   if (!ptr) {
+      return __wrap_malloc(size);
+   }
+   
+   if (__wrap_malloc_usable_size(ptr) >= size) {
+      return ptr;
+   }
+   
    void *realloc_ptr = __wrap_malloc(size);
    
-   if(realloc_ptr) {
-      memcpy(realloc_ptr, ptr, size);
-      __wrap_free(ptr);
+   if(!realloc_ptr) {
+      return NULL;
    }
    
+   memcpy(realloc_ptr, ptr, __wrap_malloc_usable_size(ptr));
+   __wrap_free(ptr);
+   
    return realloc_ptr;
 }
 
@@ -43,11 +58,6 @@ __wrap_calloc(size_t num, size_t size) {
    return ptr;
 }
 
-size_t
-__wrap_malloc_usable_size(void *ptr) {
-   return MEMGetSizeForMBlockExpHeap(ptr);
-}
-
 void *
 __wrap_valloc(size_t size) {
    return __wrap_memalign(64, size);