config: source make.conf only once if samefile

Since migration from /etc/make.conf to /etc/portage/make.conf, people
frequently ask if hardlinking or symlinking them is allowed. So, detect
this case and avoid redundant sourcing when appropriate.

diff --git a/pym/portage/package/ebuild/config.py b/pym/portage/package/ebuild/config.py
index 2a05904866e70fe133181b2231c3249181c4e919..684de16db063cbfa18fcadbc4ae4ed11c68c16de 100644 (file)
--- a/pym/portage/package/ebuild/config.py
+++ b/pym/portage/package/ebuild/config.py
@@ -301,15 +301,21 @@ class config(object):
                        eprefix = locations_manager.eprefix
                        config_root = locations_manager.config_root
                        abs_user_config = locations_manager.abs_user_config
-
-                       make_conf = getconfig(
+                       make_conf_paths = [
                                os.path.join(config_root, 'etc', 'make.conf'),
-                               tolerant=tolerant, allow_sourcing=True) or {}
+                               os.path.join(config_root, MAKE_CONF_FILE)
+                       ]
+                       try:
+                               if os.path.samefile(*make_conf_paths):
+                                       make_conf_paths.pop()
+                       except OSError:
+                               pass
 
-                       make_conf.update(getconfig(
-                               os.path.join(config_root, MAKE_CONF_FILE),
-                               tolerant=tolerant, allow_sourcing=True,
-                               expand=make_conf) or {})
+                       make_conf = {}
+                       for x in make_conf_paths:
+                               make_conf.update(getconfig(x,
+                                       tolerant=tolerant, allow_sourcing=True,
+                                       expand=make_conf) or {})
 
                        # Allow ROOT setting to come from make.conf if it's not overridden
                        # by the constructor argument (from the calling environment).
@@ -481,15 +487,11 @@ class config(object):
                        self.configlist.append(mygcfg)
                        self.configdict["defaults"]=self.configlist[-1]
 
-                       mygcfg = getconfig(
-                               os.path.join(config_root, 'etc', 'make.conf'),
-                               tolerant=tolerant, allow_sourcing=True,
-                               expand=expand_map) or {}
-
-                       mygcfg.update(getconfig(
-                               os.path.join(config_root, MAKE_CONF_FILE),
-                               tolerant=tolerant, allow_sourcing=True,
-                               expand=expand_map) or {})
+                       mygcfg = {}
+                       for x in make_conf_paths:
+                               mygcfg.update(getconfig(x,
+                                       tolerant=tolerant, allow_sourcing=True,
+                                       expand=expand_map) or {})
 
                        # Don't allow the user to override certain variables in make.conf
                        profile_only_variables = self.configdict["defaults"].get(