[MSVCRTEX] Add recalloc. CORE-20596

sdk/lib/crt/msvcrtex.cmake

@@ -8,7 +8,8 @@ list(APPEND MSVCRTEX_SOURCE
     misc/isblank.c
     misc/iswblank.c
     misc/ofmt_stub.c
-    stdio/acrt_iob_func.c)
+    stdio/acrt_iob_func.c
+    recalloc.c)
 
 if(DLL_EXPORT_VERSION LESS 0x600)
     list(APPEND MSVCRTEX_SOURCE

sdk/lib/crt/recalloc.c

@@ -0,0 +1,32 @@
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <malloc.h>
+
+void* __cdecl recalloc(void *mem, size_t num, size_t size)
+{
+    size_t old_size;
+    void *ret;
+
+    if(!mem)
+        return calloc(num, size);
+
+    size = num*size;
+    old_size = _msize(mem);
+
+    ret = realloc(mem, size);
+    if(!ret) {
+        *_errno() = ENOMEM;
+        return NULL;
+    }
+
+    if(size>old_size)
+        memset((unsigned char*)ret+old_size, 0, size-old_size);
+    return ret;
+}
+
+#ifdef _WIN64
+void* __imp__recalloc = recalloc;
+#else
+void* _imp___recalloc = recalloc;
+#endif