dev-python/python-distutils-extra: Fix --skip-build support

Closes: https://bugs.gentoo.org/718394
Signed-off-by: Michał Górny <mgorny@gentoo.org>

dev-python/python-distutils-extra/files/python-distutils-extra-2.44-skip-build.patch

@@ -0,0 +1,63 @@
+From 4f5e11110ce9cc3f511c798acfc009ce5db4e9ef Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Micha=C5=82=20G=C3=B3rny?= <mgorny@gentoo.org>
+Date: Tue, 28 Apr 2020 10:48:18 +0200
+Subject: [PATCH] Fix install_auto command with --skip-build
+
+python-distutils-extra seems to rely on a very bad practice of modifying
+internal state (file lists) in middle of `build` commands.  As a result,
+if the package is installed via `build` command followed by `install
+--skip-build` (since everything was built already!), most of the files
+are not installed.
+
+Ideally, this would be resolved by making internal state updates
+independent of `build` command execution.  However, given that
+the package is not really alive and worth the effort, let's settle
+on a cheap hack of calling all `build_*` subcommands from `install`
+if `--skip-build` is used.  This partially reverses what standard
+distutils `install` command does but it will rebuild only the data files
+rather than all C extensions.
+
+Modify tests to use `--skip-build` unconditionally to test this better.
+Testing both scenarios probably makes little sense.
+---
+ DistUtilsExtra/auto.py | 7 +++++++
+ test/auto.py           | 5 +++--
+ 2 files changed, 10 insertions(+), 2 deletions(-)
+
+diff --git a/DistUtilsExtra/auto.py b/DistUtilsExtra/auto.py
+index ea15183..db45f7a 100644
+--- a/DistUtilsExtra/auto.py
++++ b/DistUtilsExtra/auto.py
+@@ -711,6 +711,13 @@ class sdist_auto(distutils.command.sdist.sdist):
+ 
+ class install_auto(distutils.command.install.install):
+     def run(self):
++        # run build_* subcommands to get file lists if install command
++        # won't run 'build' for us
++        if self.skip_build:
++            self.run_command('build_help')
++            self.run_command('build_i18n')
++            self.run_command('build_icons')
++
+         # install files from etc/
+         if os.path.isdir('etc'):
+             # work around a bug in copy_tree() which fails with "File exists" on
+diff --git a/test/auto.py b/test/auto.py
+index b9644ba..15780c6 100755
+--- a/test/auto.py
++++ b/test/auto.py
+@@ -873,8 +873,9 @@ print ('import iamnota.module')
+         '''
+         self.install_tree = tempfile.mkdtemp()
+ 
+-        return self.setup_py(['install', '--no-compile', '--prefix=/usr',
+-            '--root=' + self.install_tree])
++        self.setup_py(['build'])
++        return self.setup_py(['install', '--no-compile', '--skip-build',
++            '--prefix=/usr', '--root=' + self.install_tree])
+ 
+     def installed_files(self):
+         '''Return list of file paths in install tree.'''
+-- 
+2.26.2
+

dev-python/python-distutils-extra/python-distutils-extra-2.44-r1.ebuild

@@ -32,6 +32,7 @@ BDEPEND="
 
 PATCHES=(
 	"${FILESDIR}"/python-distutils-extra-2.44-test.patch
+	"${FILESDIR}"/python-distutils-extra-2.44-skip-build.patch
 )
 
 python_test() {