--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mercurial/configuration/rcutil.py	Mon Oct 21 13:39:44 2024 +0200
@@ -0,0 +1,119 @@
+# rcutil.py - utilities about config paths, special config sections etc.
+#
+#  Copyright Mercurial Contributors
+#
+# This software may be used and distributed according to the terms of the
+# GNU General Public License version 2 or any later version.
+
+from __future__ import annotations
+
+import os
+
+from .. import (
+    encoding,
+    pycompat,
+    util,
+)
+
+from ..utils import resourceutil
+
+if pycompat.iswindows:
+    from .. import scmwindows as scmplatform
+else:
+    from .. import scmposix as scmplatform
+
+fallbackpager = scmplatform.fallbackpager
+systemrcpath = scmplatform.systemrcpath
+userrcpath = scmplatform.userrcpath
+
+
+def _expandrcpath(path):
+    '''path could be a file or a directory. return a list of file paths'''
+    p = util.expandpath(path)
+    if os.path.isdir(p):
+        join = os.path.join
+        return sorted(
+            join(p, f) for f, k in util.listdir(p) if f.endswith(b'.rc')
+        )
+    return [p]
+
+
+def envrcitems(env=None):
+    """Return [(section, name, value, source)] config items.
+
+    The config items are extracted from environment variables specified by env,
+    used to override systemrc, but not userrc.
+
+    If env is not provided, encoding.environ will be used.
+    """
+    if env is None:
+        env = encoding.environ
+    checklist = [
+        (b'EDITOR', b'ui', b'editor'),
+        (b'VISUAL', b'ui', b'editor'),
+        (b'PAGER', b'pager', b'pager'),
+    ]
+    result = []
+    for envname, section, configname in checklist:
+        if envname not in env:
+            continue
+        result.append((section, configname, env[envname], b'$%s' % envname))
+    return result
+
+
+def default_rc_resources():
+    """return rc resource IDs in defaultrc"""
+    rsrcs = resourceutil.contents(b'mercurial.defaultrc')
+    return [
+        (b'mercurial.defaultrc', r)
+        for r in sorted(rsrcs)
+        if resourceutil.is_resource(b'mercurial.defaultrc', r)
+        and r.endswith(b'.rc')
+    ]
+
+
+def rccomponents():
+    """return an ordered [(type, obj)] about where to load configs.
+
+    respect $HGRCPATH. if $HGRCPATH is empty, only .hg/hgrc of current repo is
+    used. if $HGRCPATH is not set, the platform default will be used.
+
+    if a directory is provided, *.rc files under it will be used.
+
+    type could be either 'path', 'items' or 'resource'. If type is 'path',
+    obj is a string, and is the config file path. if type is 'items', obj is a
+    list of (section, name, value, source) that should fill the config directly.
+    If type is 'resource', obj is a tuple of (package name, resource name).
+    """
+    envrc = (b'items', envrcitems())
+
+    if b'HGRCPATH' in encoding.environ:
+        # assume HGRCPATH is all about user configs so environments can be
+        # overridden.
+        _rccomponents = [envrc]
+        for p in encoding.environ[b'HGRCPATH'].split(pycompat.ospathsep):
+            if not p:
+                continue
+            _rccomponents.extend((b'path', p) for p in _expandrcpath(p))
+    else:
+        _rccomponents = [(b'resource', r) for r in default_rc_resources()]
+
+        normpaths = lambda paths: [
+            (b'path', os.path.normpath(p)) for p in paths
+        ]
+        _rccomponents.extend(normpaths(systemrcpath()))
+        _rccomponents.append(envrc)
+        _rccomponents.extend(normpaths(userrcpath()))
+    return _rccomponents
+
+
+def defaultpagerenv():
+    """return a dict of default environment variables and their values,
+    intended to be set before starting a pager.
+    """
+    return {b'LESS': b'FRX', b'LV': b'-c'}
+
+
+def use_repo_hgrc():
+    """True if repositories `.hg/hgrc` config should be read"""
+    return b'HGRCSKIPREPO' not in encoding.environ