From 21e918a8f6e0fd144287ff7fc2ab3d262ac9edd7 Mon Sep 17 00:00:00 2001
From: Joe Gordon <jogo@cloudscaling.com>
Date: Fri, 13 Apr 2012 15:12:04 -0400
Subject: [PATCH] Fix bug 983206 : _try_convert parsing string

* _try_convert in ec2utils.py didn't handle strings starting with "0x"
* Added tests to cover bug
* Add better float support
* remove unused complex number support

Change-Id: I382d36f4a8671bcceccfa1ebdbae89a9d2aca207
(cherry picked from commit c95162e52899618fc269fb536f6a2d3b26b7794d)
---
 nova/api/ec2/ec2utils.py |   35 +++++++++++------------------------
 nova/tests/test_api.py   |   12 ++++++++++++
 2 files changed, 23 insertions(+), 24 deletions(-)

diff --git a/nova/api/ec2/ec2utils.py b/nova/api/ec2/ec2utils.py
index 1a6bb96..0f4aeb0 100644
--- a/nova/api/ec2/ec2utils.py
+++ b/nova/api/ec2/ec2utils.py
@@ -166,6 +166,10 @@ def _try_convert(value):
     *             try conversion to int, float, complex, fallback value
 
     """
+    def _negative_zero(value):
+        epsilon = 1e-7
+        return 0 if abs(value) < epsilon else value
+
     if len(value) == 0:
         return ''
     if value == 'None':
@@ -175,31 +179,14 @@ def _try_convert(value):
         return True
     if lowered_value == 'false':
         return False
-    valueneg = value[1:] if value[0] == '-' else value
-    if valueneg == '0':
-        return 0
-    if valueneg == '':
-        return value
-    if valueneg[0] == '0':
-        if valueneg[1] in 'xX':
-            return int(value, 16)
-        elif valueneg[1] in 'bB':
-            return int(value, 2)
-        else:
-            try:
-                return int(value, 8)
-            except ValueError:
-                pass
-    try:
-        return int(value)
-    except ValueError:
-        pass
-    try:
-        return float(value)
-    except ValueError:
-        pass
+    for prefix, base in [('0x', 16), ('0b', 2), ('0', 8), ('', 10)]:
+        try:
+            if lowered_value.startswith((prefix, "-" + prefix)):
+                return int(lowered_value, base)
+        except ValueError:
+            pass
     try:
-        return complex(value)
+        return _negative_zero(float(value))
     except ValueError:
         return value
 
diff --git a/nova/tests/test_api.py b/nova/tests/test_api.py
index baaee98..a52319f 100644
--- a/nova/tests/test_api.py
+++ b/nova/tests/test_api.py
@@ -96,8 +96,10 @@ class XmlConversionTestCase(test.TestCase):
         conv = ec2utils._try_convert
         self.assertEqual(conv('None'), None)
         self.assertEqual(conv('True'), True)
+        self.assertEqual(conv('TRUE'), True)
         self.assertEqual(conv('true'), True)
         self.assertEqual(conv('False'), False)
+        self.assertEqual(conv('FALSE'), False)
         self.assertEqual(conv('false'), False)
         self.assertEqual(conv('0'), 0)
         self.assertEqual(conv('42'), 42)
@@ -107,6 +109,16 @@ class XmlConversionTestCase(test.TestCase):
         self.assertEqual(conv('-0x57'), -0x57)
         self.assertEqual(conv('-'), '-')
         self.assertEqual(conv('-0'), 0)
+        self.assertEqual(conv('0.0'), 0.0)
+        self.assertEqual(conv('1e-8'), 0.0)
+        self.assertEqual(conv('-1e-8'), 0.0)
+        self.assertEqual(conv('0xDD8G'), '0xDD8G')
+        self.assertEqual(conv('0XDD8G'), '0XDD8G')
+        self.assertEqual(conv('-stringy'), '-stringy')
+        self.assertEqual(conv('stringy'), 'stringy')
+        self.assertEqual(conv('add'), 'add')
+        self.assertEqual(conv('remove'), 'remove')
+        self.assertEqual(conv(''), '')
 
 
 class Ec2utilsTestCase(test.TestCase):