Make 'import portage' statements more tolerant to broken source statements

in make.conf since exceptions thrown during 'import portage' statements
can practically render the api unusable for api consumers. Thanks to lxnay
for the suggestion.

svn path=/main/trunk/; revision=9400

2 files changed, 28 insertions, 3 deletions

diff --git a/pym/portage/__init__.py b/pym/portage/__init__.py
index e8a8f4f25..dfbe70fc2 100644
--- a/pym/portage/__init__.py
+++ b/pym/portage/__init__.py
@@ -969,7 +969,11 @@ class config(object):
 		@type local_config: Boolean
 		"""
 
-		debug = os.environ.get("PORTAGE_DEBUG") == "1"
+		# When initializing the global portage.settings instance, avoid
+		# raising exceptions whenever possible since exceptions thrown
+		# from 'import portage' or 'import portage.exceptions' statements
+		# can practically render the api unusable for api consumers.
+		tolerant = "_initializing_globals" in globals()
 
 		self.already_in_regenerate = 0
 
@@ -1244,7 +1248,7 @@ class config(object):
 
 			self.mygcfg = getconfig(
 				os.path.join(config_root, MAKE_CONF_FILE.lstrip(os.path.sep)),
-				allow_sourcing=True)
+				tolerant=tolerant, allow_sourcing=True)
 			if self.mygcfg is None:
 				self.mygcfg = {}
 
@@ -6284,7 +6288,10 @@ def init_legacy_globals():
 	for k, envvar in (("config_root", "PORTAGE_CONFIGROOT"), ("target_root", "ROOT")):
 		kwargs[k] = os.environ.get(envvar, "/")
 
+	global _initializing_globals
+	_initializing_globals = True
 	db = create_trees(**kwargs)
+	del _initializing_globals
 
 	settings = db["/"]["vartree"].settings
 	portdb = db["/"]["porttree"].dbapi
diff --git a/pym/portage/util.py b/pym/portage/util.py
index 97c785c06..155a787f5 100644
--- a/pym/portage/util.py
+++ b/pym/portage/util.py
@@ -21,6 +21,11 @@ try:
 except ImportError:
 	import pickle as cPickle
 
+try:
+	import cStringIO as StringIO
+except ImportError:
+	import StringIO
+
 noiselimit = 0
 
 def initialize_logger(level=logging.WARN):
@@ -305,6 +310,15 @@ def writedict(mydict,myfilename,writekey=True):
 		return 0
 	return 1
 
+class _tolerant_shlex(shlex.shlex):
+	def sourcehook(self, newfile):
+		try:
+			return shlex.shlex.sourcehook(self, newfile)
+		except EnvironmentError, e:
+			writemsg("!!! Parse error in '%s': source command failed: %s\n" % \
+				(self.infile, str(e)), noiselevel=-1)
+			return (newfile, StringIO.StringIO())
+
 def getconfig(mycfg, tolerant=0, allow_sourcing=False, expand=True):
 	mykeys={}
 	try:
@@ -316,10 +330,14 @@ def getconfig(mycfg, tolerant=0, allow_sourcing=False, expand=True):
 			raise
 		return None
 	try:
+		if tolerant:
+			shlex_class = _tolerant_shlex
+		else:
+			shlex_class = shlex.shlex
 		# The default shlex.sourcehook() implementation
 		# only joins relative paths when the infile
 		# attribute is properly set.
-		lex = shlex.shlex(f, infile=mycfg, posix=True)
+		lex = shlex_class(f, infile=mycfg, posix=True)
 		lex.wordchars=string.digits+string.letters+"~!@#$%*_\:;?,./-+{}"     
 		lex.quotes="\"'"
 		if allow_sourcing: