From 97d78cd3f204010a1cedef481a52829931435adc Mon Sep 17 00:00:00 2001
From: Sebastian Luther <SebastianLuther@gmx.de>
Date: Wed, 18 Aug 2010 14:58:19 +0200
Subject: [PATCH] use_reduce: code cleanup

---
 pym/portage/dep/__init__.py              | 56 +++++++++++-------------
 pym/portage/tests/dep/test_use_reduce.py | 11 +++--
 2 files changed, 33 insertions(+), 34 deletions(-)

diff --git a/pym/portage/dep/__init__.py b/pym/portage/dep/__init__.py
index 643bc56d7..98d248938 100644
--- a/pym/portage/dep/__init__.py
+++ b/pym/portage/dep/__init__.py
@@ -340,6 +340,7 @@ def use_reduce(depstr, uselist=[], masklist=[], matchall=False, excludeall=[], i
 			if level > 0:
 				level -= 1
 				l = stack.pop()
+				is_single = (len(l) == 1 or (len(l)==2 and l[0] == "||"))
 				ignore = False
 
 				if flat:
@@ -369,42 +370,43 @@ def use_reduce(depstr, uselist=[], masklist=[], matchall=False, excludeall=[], i
 							ignore = True
 						stack[level].pop()
 
+				def ends_in_any_of_dep(k):
+					return k>=0 and stack[k] and stack[k][-1] == "||"
+
+				def special_append():
+					"""
+					Use extend instead of append if possible. This kills all redundant brackets.
+					"""
+					if is_single:
+						if len(l) == 1 and isinstance(l[0], list):
+							# l = [[...]]
+							stack[level].extend(l[0])
+						else:
+							stack[level].extend(l)
+					else:	
+						stack[level].append(l)
+
 				if l and not ignore:
 					#The current list is not empty and we don't want to ignore it because
 					#of an inactive use conditional.
-					if not (level>0 and stack[level-1] and stack[level-1][-1] == "||") \
-						and (not stack[level] or stack[level][-1] != "||"):
-						#Optimize: ( ( ... ) ) -> ( ... )
+					if not ends_in_any_of_dep(level-1) and not ends_in_any_of_dep(level):
+						#Optimize: ( ( ... ) ) -> ( ... ). Make sure there is no '||' hanging around.
 						stack[level].extend(l)
 					elif not stack[level]:
-						stack[level].append(l)
-					elif len(l) == 1 and stack[level][-1] == "||":
-						#Optimize: || ( A ) -> A
+						#An '||' in the level above forces us to keep to brackets.
+						special_append()
+					elif is_single and ends_in_any_of_dep(level):
+						#Optimize: || ( A ) -> A,  || ( || ( ... ) ) -> || ( ... )
 						stack[level].pop()
-						stack[level].extend(l)
-					elif len(l) == 2 and l[0] == "||" and stack[level][-1] == "||":
-						#Optimize: 	|| ( || ( ... ) ) -> || ( ... )
-						stack[level].pop()
-						stack[level].extend(l)
+						special_append()
 					else:
-						if opconvert and stack[level] and stack[level][-1] == "||":
+						if opconvert and ends_in_any_of_dep(level):
 							#In opconvert mode, we have to move the operator from the level
 							#above into the current list.
 							stack[level].pop()
 							stack[level].append(["||"] + l)
 						else:
-							stack[level].append(l)
-
-				if level > 0 and stack[level-1] and stack[level-1][-1] == "||":
-					all_singles = True
-					for x in stack[level]:
-						if isinstance(x, list) and len(x) > 1:
-							all_singles =  False
-							break
-					if all_singles:
-						for i, x in enumerate(stack[level]):
-							if isinstance(x, list):
-								stack[level][i] = x[0]
+							special_append()
 
 			else:
 				raise portage.exception.InvalidDependString(
@@ -468,12 +470,6 @@ def use_reduce(depstr, uselist=[], masklist=[], matchall=False, excludeall=[], i
 		raise portage.exception.InvalidDependString(
 			_("Missing file name at end of string: '%s'") % (depstr,))
 
-	if len(stack[0]) == 1 and isinstance(stack[0][0], list):
-		if opconvert and stack[0][0] and stack[0][0][0] == "||":
-			pass
-		else:
-			stack[0] = stack[0][0]
-
 	return stack[0]
 
 def dep_opconvert(deplist):
diff --git a/pym/portage/tests/dep/test_use_reduce.py b/pym/portage/tests/dep/test_use_reduce.py
index 6d4438979..deaae91f2 100644
--- a/pym/portage/tests/dep/test_use_reduce.py
+++ b/pym/portage/tests/dep/test_use_reduce.py
@@ -172,6 +172,9 @@ class UseReduce(TestCase):
 			UseReduceTestCase(
 				"|| ( ( A B ) C )",
 				expected_result = [ "||", [ ["A", "B"], "C"] ]),
+			UseReduceTestCase(
+				"|| ( ( A B ) ( C ) )",
+				expected_result = [ "||", [ ["A", "B"], "C"] ]),
 			UseReduceTestCase(
 				"|| ( A || ( B C ) )",
 				expected_result = [ "||", ["A", "||", ["B", "C"]]]),
@@ -293,11 +296,11 @@ class UseReduce(TestCase):
 			UseReduceTestCase(
 				"( || ( || ( ( A ) B ) ) )",
 				opconvert = True,
-				expected_result = [ ["||", "A", "B"] ]),
+				expected_result = ["||", "A", "B"]),
 			UseReduceTestCase(
 				"( || ( || ( ( A ) B ) ) )",
 				opconvert = True,
-				expected_result = [ ["||", "A", "B"] ]),
+				expected_result = ["||", "A", "B"]),
 			UseReduceTestCase(
 				"|| ( A )",
 				opconvert = True,
@@ -309,7 +312,7 @@ class UseReduce(TestCase):
 				"( || ( || ( || ( A ) foo? ( B ) ) ) )",
 				uselist = ["foo"],
 				opconvert = True,
-				expected_result = [ ["||", "A", "B"] ]),
+				expected_result = ["||", "A", "B"]),
 			UseReduceTestCase(
 				"( || ( || ( bar? ( A ) || ( foo? ( B ) ) ) ) )",
 				opconvert = True,
@@ -318,7 +321,7 @@ class UseReduce(TestCase):
 				"( || ( || ( bar? ( A ) || ( foo? ( B ) ) ) ) )",
 				uselist = ["foo", "bar"],
 				opconvert = True,
-				expected_result = [ ["||", "A", "B"] ]),
+				expected_result = ["||", "A", "B"]),
 			UseReduceTestCase(
 				"A || ( ) foo? ( ) B",
 				opconvert = True,
-- 
2.26.2