Merge "Handle additional directory structures in image upload"
diff --git a/stack.sh b/stack.sh
index a7ed1b9..1edc44f 100755
--- a/stack.sh
+++ b/stack.sh
@@ -1650,6 +1650,8 @@
 
         KERNEL=""
         RAMDISK=""
+        DISK_FORMAT=""
+        CONTAINER_FORMAT=""
         case "$IMAGE_FNAME" in
             *.tar.gz|*.tgz)
                 # Extract ami and aki files