sphinx.ext.graphviz: custom node shape images are not copied to _images at building

[Tilix4]

Describe the bug
A clear and concise description of what the bug is.

To Reproduce
Steps to reproduce the behavior:

• Start from autodoc

• Unzip this archive in source: graphviz_image_copy_issue.zip

• Build the doc: make html

• Display the built doc in a browser

• The graph doesn't display the declared image in the custom node.

• Now copy the film.svg file manually into build/html/_images

• Refresh the documentation in the browser, the custom shape displays correctly

Expected behavior
The targetted image to be copied in build/html/_images by default.

Your project
Link to your sphinx project, or attach zipped small project sample.

Screenshots
If applicable, add screenshots to help explain your problem.

Environment info

• OS: Mac 10.14.5
• Python version: 3.7.7
• Sphinx version: 3.2.1
• Sphinx extensions: sphinx.ext.graphviz

[tk0miya]

This report contains a bug and a feature request.

The first is a bug that graphviz failed to find the image files if the image source (.dot) file is placed at sub directory. It was caused that our graphviz extension invokes dot command just under the source directory. I confirmed the bug with graphviz_output_format = 'png' (default setting).

And another one is the image files refered from the image source are not copied. It is happened when graphviz_output_format = 'svg'. The current implementation of graphviz extension only invokes graphviz to convert the graph to image. It does not copy the images referred inside graph. To support it, we need to parse and detect images referred by the image source and copy them all to the output directory.

[tk0miya]

I posted #8766 to fix the bug.

[tk0miya]

Note: I think pydot might help to parse the graph file.
https://github.com/pydot/pydot

[alexander-nitsche]

Hi @tk0miya ,

i am still facing the bug in Sphinx v4.3.1 (latest).

For example for source files

• /Documentation/WritingReST/Graphs.rst
• /Documentation/WritingReST/typo3.png

and the minimal reST snippet:

.. graphviz::

   digraph {
      typo3 [
         image="typo3.png"
         label=""
      ]
    }

the image does not get copied to /Documentation-GENERATED-temp/Result/project/0.0.0/_images/typo3.png and thus the image url is not resolvable in /Documentation-GENERATED-temp/Result/project/0.0.0/_images/graphviz-6d1b84d1ecedd782b117d9a9791de374e2ea939e.svg:

<image xlink:href="typo3.png" width="482px" height="204px" preserveAspectRatio="xMinYMin meet" x="15.6798" y="-211.602"/>

[tk0miya]

@alexander-nitsche Thanks,
As you reported, the images referred the graph are not copied. So we need to parse the graph and find the images to copy them. How about trying to improve it?

[alexander-nitsche]

hi @tk0miya , if sphinx would be written in PHP i would do it but have to stick to provide bug report details for the moment.

[tk0miya]

Okay, don't mind.