Remote image URIs without filename break HTML builds in 1.6.2

[jantman]

Subject: Remote image URIs without filename break HTML builds in 1.6.2

Problem

• Remote image URIs that lack a filename, such as readthedocs.org status badges which are URIs of the form https://readthedocs.org/projects/PROJECT-NAME/badge/?version=latest (note there is no explicit filename here), break the HTML builder.

Procedure to reproduce the problem

Attempt building a project which includes an image like the above in a file, such as README.rst, using Sphinx 1.6.2. i.e.:

.. image:: https://readthedocs.org/projects/awslimitchecker/badge/?version=latest
   :target: https://readthedocs.org/projects/awslimitchecker/?badge=latest
   :alt: sphinx documentation for latest release

https://readthedocs.org/projects/awslimitchecker/badge/?version=latest actually redirects to https://img.shields.io/badge/docs-latest-brightgreen.svg?style=flat - the URL checks the status of the docs build for the specified version, and redirects to an appropriate shields.io badge.

Build with:

sphinx-build -a -n -W -b linkcheck docs/source docs/build/html

Error logs / results

Warning, treated as error:
Could not fetch remote image: https://readthedocs.org/projects/awslimitchecker/badge/?version=latest [[Errno 21] Is a directory: u'/home/jantman/GIT/awslimitchecker/docs/build/html/.doctrees/images/https/readthedocs.org/projects/awslimitchecker/badge//version=latest/']

• https://travis-ci.org/jantman/awslimitchecker/jobs/241720146

From what I can tell, the problem seems to be in sphinx.transforms.post_transforms.images.ImageDownloader.handle as introduced in #3589, as the local paths that it generates do not work for images without a filename (basename) in the URI.

Expected results

Expected these images to download correctly without a problem, as they did under 1.5.5

Reproducible project / your project

• https://github.com/jantman/awslimitchecker

Environment info

• OS: Linux (Arch, or whatever TravisCI and readthedocs.org run)
• Python version: 2.7.13
• Sphinx version: 1.6.2

[jfbu]

I can not reproduce your problem with minimal index.rst containing only

Welcome to FOO's documentation!
===============================

.. image:: https://readthedocs.org/projects/awslimitchecker/badge/?version=latest
   :target: https://readthedocs.org/projects/awslimitchecker/?badge=latest
   :alt: sphinx documentation for latest release

and

# Sphinx version: 1.6.2
# Python version: 2.7.13 (CPython)
# Docutils version: 0.13.1 release
# Jinja2 version: 2.9.6

on mac os. Also tested with Python 3.5.3.

[jfbu]

apologies, yes indeed using the sphinx-build

$ sphinx-build -a -n -W -b linkcheck . _build/html

as you said. By the way on Sphinx 1.5.6, the same Warning is issued without even activating linkcheck.

[jfbu]

Well, sorry again, there is the problem even without linkcheck.

Error: No error with 1.6.2, but error with 1.5.6:

$ sphinx-build -a -n -W  . _build/html

No Error:

$ make clean html O="-a -n -W"

Again Error:

$ make clean html O="-b linkcheck -W"

Or simply one gets the warning via

 $ make clean linkcheck

Looks as if linkcheck needs update

[jantman]

Ok, thank you. Apologies for not posting a gist or repo, or some quicker way for you to reproduce the issue.

[tk0miya]

Fixed by #3890.
Thank you for reporting!