Duplicate nodes created for external images

[iamthad]

When I use multiple copies of an external image, multiple nodes pop up for them, even though edges only come from one node.

For example,

# syntax=docker/dockerfile:1.4

FROM scratch AS download-node-setup
ADD https://deb.nodesource.com/setup_16.x ./

FROM scratch AS download-get-pip
ADD https://bootstrap.pypa.io/get-pip.py ./

FROM alpine AS final
COPY --from=download-node-setup setup_16.x ./
COPY --from=download-get-pip get-pip.py ./

makes two nodes for "scratch":

[patrickhoefler]

Thanks for the excellent bug report, should be fixed now 🙂