[Piglit] [PATCH] framework: fix potential bug in function signatures

[Dylan Baker]

It seems perfectly safe to do something like this:
def foo(defaults=[]):
     <stuff>

But its not. Python will only initialize defaults once, and store it.
Which means each time that foo is called with arguments defaults is
changed. So when calling foo() more than once with arguments unexpected
things can happen. This can create some very strange and hard to pin
down bugs.

Signed-off-by: Dylan Baker <baker.dylan.c at gmail.com>
---
 framework/core.py | 14 ++++++++------
 tests/igt.py      |  4 +++-
 2 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/framework/core.py b/framework/core.py
index 3979499..ac5be2b 100644
--- a/framework/core.py
+++ b/framework/core.py
@@ -344,8 +344,8 @@ class TestrunResult:
 
 
 class Environment:
-    def __init__(self, concurrent=True, execute=True, include_filter=[],
-                 exclude_filter=[], valgrind=False, dmesg=False, verbose=False):
+    def __init__(self, concurrent=True, execute=True, include_filter=None,
+                 exclude_filter=None, valgrind=False, dmesg=False, verbose=False):
         self.concurrent = concurrent
         self.execute = execute
         self.filter = []
@@ -361,10 +361,12 @@ class Environment:
 
         This code uses re.compile to rebuild the lists and set self.filter
         """
-        for each in include_filter:
-            self.filter.append(re.compile(each))
-        for each in exclude_filter:
-            self.exclude_filter.append(re.compile(each))
+        if include_filter is not None:
+            for each in include_filter:
+                self.filter.append(re.compile(each))
+        if exclude_filter is not None:
+            for each in exclude_filter:
+                self.exclude_filter.append(re.compile(each))
 
     def __iter__(self):
         for key, values in self.__dict__.iteritems():
diff --git a/tests/igt.py b/tests/igt.py
index 9c700a9..766f543 100644
--- a/tests/igt.py
+++ b/tests/igt.py
@@ -72,7 +72,9 @@ igtEnvironmentOk = checkEnvironment()
 profile = TestProfile()
 
 class IGTTest(Test):
-    def __init__(self, binary, arguments=[]):
+    def __init__(self, binary, arguments=None):
+        if arguments is None:
+            arguments = []
         super(IGTTest, self).__init__(
             [path.join(igtTestRoot, binary)] + arguments)
 
-- 
1.9.2