1 files changed, 12 insertions, 4 deletions
diff --git a/src/core/basetypes/MCDataMac.mm b/src/core/basetypes/MCDataMac.mm
index 8081b1f9..589e8b59 100644
--- a/src/core/basetypes/MCDataMac.mm
+++ b/src/core/basetypes/MCDataMac.mm
@@ -14,9 +14,17 @@ using namespace mailcore;
 
 CFDataRef Data::destructiveNSData()
 {
-    NSData * result = [NSData dataWithBytesNoCopy:(void *) mBytes length:mLength];
-    mBytes = NULL;
-    mAllocated = 0;
-    mLength = 0;
+    NSData * result;
+    if (mExternallyAllocatedMemory) {
+        BytesDeallocator deallocator = mBytesDeallocator;
+        result = [[[NSData alloc] initWithBytesNoCopy:mBytes length:mLength deallocator:^(void * bytes, NSUInteger length) {
+            if (deallocator) {
+                deallocator((char *)bytes, (unsigned int)length);
+            }
+        }] autorelease];
+    } else {
+        result = [NSData dataWithBytesNoCopy:(void *) mBytes length:mLength];
+    }
+    init();
     return (CFDataRef) result;
 }