[PR] Fixed pointer overflow crash when using bgsave under rare circum…

…stances.

(cherry picked from commit 0707007)

src/Win32_Interop/Win32_Common.cpp

@@ -38,10 +38,9 @@ void EnsureMemoryIsMapped(const void *buffer, size_t size) {
     if ((size_t) (pEnd - pStart) > Globals::pageSize) {
         size_t offset = 0;
         while (offset < size) {
-            if (size < offset) {
+            offset += Globals::pageSize;
+            if (offset > size) {
                 offset = size;
-            } else {
-                offset += Globals::pageSize;
             }
             c = *((char*) (p + offset));
         }
@@ -62,4 +61,4 @@ bool IsWindowsVersionAtLeast(WORD wMajorVersion, WORD wMinorVersion, WORD wServi
     osvi.wServicePackMajor = wServicePackMajor;
 
     return VerifyVersionInfoW(&osvi, VER_MAJORVERSION | VER_MINORVERSION | VER_SERVICEPACKMAJOR, dwlConditionMask) != FALSE;
-}
+}