Build script fixes

latex/build-image.sh

@@ -3,11 +3,15 @@
 echo "Build will be tagged with $1"
 echo "Build directory is $(pwd)"
 
-OLD_IMG=docker image ls -q "$1"
+OLD_IMG=$(docker image ls -q "$1")
 docker buildx build . -t "$1"
 
 echo "Build complete, starting upload..."
 docker push "$1"
 
+if [[ -n "$OLD_IMG" ]]; then
+	if [[ "$OLD_IMG" != "$(docker image ls -q "$1")" ]]; then
 		echo "New build uploaded, removing old image, id: $OLD_IMG"
 		docker image rm "$OLD_IMG"
+	fi
+fi