From 19c0511f571aa19d0448d36817c81657a782c050 Mon Sep 17 00:00:00 2001
From: Matt Clay <matt@mystile.com>
Date: Mon, 8 Oct 2018 12:47:39 -0700
Subject: [PATCH] Add link check to `make sdist`.

This will cause `make sdist` to fail on platforms which create
hard links of symbolic links as regular files, such as MacOS (Darwin).

This prevents accidental creation of an sdist tarball without
the necessary symbolic links.
---
 Makefile                               |  6 ++-
 packaging/sdist/check-link-behavior.py | 51 ++++++++++++++++++++++++++
 2 files changed, 56 insertions(+), 1 deletion(-)
 create mode 100755 packaging/sdist/check-link-behavior.py

diff --git a/Makefile b/Makefile
index a7d21b3a600..c5b01199322 100644
--- a/Makefile
+++ b/Makefile
@@ -231,8 +231,12 @@ install_manpages:
 	gzip -9 $(wildcard ./docs/man/man1/ansible*.1)
 	cp $(wildcard ./docs/man/man1/ansible*.1.gz) $(PREFIX)/man/man1/
 
+.PHONY: sdist_check
+sdist_check:
+	$(PYTHON) packaging/sdist/check-link-behavior.py
+
 .PHONY: sdist
-sdist: clean docs
+sdist: sdist_check clean docs
 	$(PYTHON) setup.py sdist
 
 .PHONY: sdist_upload
diff --git a/packaging/sdist/check-link-behavior.py b/packaging/sdist/check-link-behavior.py
new file mode 100755
index 00000000000..34e05023d48
--- /dev/null
+++ b/packaging/sdist/check-link-behavior.py
@@ -0,0 +1,51 @@
+#!/usr/bin/env python
+"""Checks for link behavior required for sdist to retain symlinks."""
+
+from __future__ import (absolute_import, division, print_function)
+
+__metaclass__ = type
+
+import os
+import platform
+import shutil
+import sys
+import tempfile
+
+
+def main():
+    """Main program entry point."""
+    temp_dir = tempfile.mkdtemp()
+
+    target_path = os.path.join(temp_dir, 'file.txt')
+    symlink_path = os.path.join(temp_dir, 'symlink.txt')
+    hardlink_path = os.path.join(temp_dir, 'hardlink.txt')
+
+    try:
+        with open(target_path, 'w'):
+            pass
+
+        os.symlink(target_path, symlink_path)
+        os.link(symlink_path, hardlink_path)
+
+        if not os.path.islink(symlink_path):
+            abort('Symbolic link not created.')
+
+        if not os.path.islink(hardlink_path):
+            # known issue on MacOS (Darwin)
+            abort('Hard link of symbolic link created as a regular file.')
+    finally:
+        shutil.rmtree(temp_dir)
+
+
+def abort(reason):
+    """
+    :type reason: str
+    """
+    sys.exit('ERROR: %s\n'
+             'This will prevent symbolic links from being preserved in the resulting tarball.\n'
+             'Aborting creation of sdist on platform: %s'
+             % (reason, platform.system()))
+
+
+if __name__ == '__main__':
+    main()