[PATCH v2 1/1] patman: additionally honor a local .patman config file

[Maxim Cournoyer]

This enables versioning a project specific patman configuration file.
It also makes it possible to declare the project name, which is not a
useful thing to do in $HOME/.patman.  A new test is added, along
updated documentation.

Signed-off-by: Maxim Cournoyer <maxim.cournoyer at savoirfairelinux.com>
---

Changes in v2:
- Explicitly provide an empty args list to parse_known_args in test

 tools/patman/patman.rst       |  8 ++++++-
 tools/patman/settings.py      | 24 +++++++++++++++----
 tools/patman/test_settings.py | 43 +++++++++++++++++++++++++++++++++++
 3 files changed, 70 insertions(+), 5 deletions(-)
 create mode 100644 tools/patman/test_settings.py

diff --git a/tools/patman/patman.rst b/tools/patman/patman.rst
index b06399b459..3e12251f03 100644
--- a/tools/patman/patman.rst
+++ b/tools/patman/patman.rst
@@ -74,7 +74,7 @@ out where to send patches pretty well.
 During the first run patman creates a config file for you by taking the default
 user name and email address from the global .gitconfig file.
 
-To add your own, create a file ~/.patman like this::
+To add your own, create a file `~/.patman` like this::
 
     # patman alias file
 
@@ -85,6 +85,12 @@ To add your own, create a file ~/.patman like this::
     wolfgang: Wolfgang Denk <wd at denx.de>
     others: Mike Frysinger <vapier at gentoo.org>, Fred Bloggs <f.bloggs at napier.net>
 
+Patman will also look for a `.patman` configuration file at the root
+of the current project git repository, which makes it possible to
+override the `project` settings variable or anything else in a
+project-specific way. The values of this "local" configuration file
+take precedence over those of the "global" one.
+
 Aliases are recursive.
 
 The checkpatch.pl in the U-Boot tools/ subdirectory will be located and
diff --git a/tools/patman/settings.py b/tools/patman/settings.py
index c05efd2475..636983e32d 100644
--- a/tools/patman/settings.py
+++ b/tools/patman/settings.py
@@ -1,5 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0+
 # Copyright (c) 2011 The Chromium OS Authors.
+# Copyright (c) 2022 Maxim Cournoyer <maxim.cournoyer at savoirfairelinux.com>
 #
 
 try:
@@ -336,6 +337,12 @@ def GetItems(config, section):
 def Setup(parser, project_name, config_fname=None):
     """Set up the settings module by reading config files.
 
+    Unless `config_fname` is specified, a `.patman` config file local
+    to the git repository is consulted, followed by the global
+    `$HOME/.patman`. If none exists, the later is created. Values
+    defined in the local config file take precedence over those
+    defined in the global one.
+
     Args:
         parser:         The parser to update.
         project_name:   Name of project that we're working on; we'll look
@@ -352,12 +359,21 @@ def Setup(parser, project_name, config_fname=None):
 
     if not config_fname:
         config_fname = '%s/.patman' % os.getenv('HOME')
+    has_config = os.path.exists(config_fname)
 
-    if not os.path.exists(config_fname):
-        print("No config file found ~/.patman\nCreating one...\n")
-        CreatePatmanConfigFile(config_fname)
+    git_local_config_fname = os.path.join(gitutil.get_top_level(), '.patman')
+    has_git_local_config = os.path.exists(git_local_config_fname)
 
-    config.read(config_fname)
+    # Read the git local config last, so that its values override
+    # those of the global config, if any.
+    if has_config:
+        config.read(config_fname)
+    if has_git_local_config:
+        config.read(git_local_config_fname)
+
+    if not (has_config or has_git_local_config):
+        print("No config file found.\nCreating ~/.patman...\n")
+        CreatePatmanConfigFile(config_fname)
 
     for name, value in GetItems(config, 'alias'):
         alias[name] = value.split(',')
diff --git a/tools/patman/test_settings.py b/tools/patman/test_settings.py
new file mode 100644
index 0000000000..b2f825f798
--- /dev/null
+++ b/tools/patman/test_settings.py
@@ -0,0 +1,43 @@
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Copyright (c) 2022 Maxim Cournoyer <maxim.cournoyer at savoirfairelinux.com>
+#
+
+import argparse
+import contextlib
+import os
+import subprocess
+import tempfile
+
+from patman import settings
+
+
+ at contextlib.contextmanager
+def empty_git_repository():
+    with tempfile.TemporaryDirectory() as tmpdir:
+        os.chdir(tmpdir)
+        subprocess.check_call(['git', 'init'])
+        yield tmpdir
+
+
+def test_git_local_config():
+    with empty_git_repository():
+        with tempfile.NamedTemporaryFile() as global_config:
+            global_config.write(b'[settings]\n'
+                                b'project=u-boot\n')
+            global_config.flush()
+            parser = argparse.ArgumentParser()
+            parser.add_argument('-p', '--project', default='unknown')
+
+            # Test "global" config is used.
+            settings.Setup(parser, 'unknown', global_config.name)
+            args, _ = parser.parse_known_args([])
+            assert args.project == 'u-boot'
+
+            # Test local config can shadow it.
+            with open('.patman', 'w', buffering=1) as f:
+                f.write('[settings]\n'
+                        'project=guix-patches\n')
+            settings.Setup(parser, 'unknown', global_config.name)
+            args, _ = parser.parse_known_args([])
+            assert args.project == 'guix-patches'
-- 
2.38.1