fix regression with environment markers handling

Ensure the result of str(Requirement()) is itself a valid
requirement line that can be parsed back.

pip/_vendor/packaging/markers.py

@@ -56,11 +56,15 @@ def __repr__(self):
 
 
 class Variable(Node):
- pass
+
+ def __str__(self):
+ return self.value
 
 
 class Value(Node):
- pass
+
+ def __str__(self):
+ return repr(str(self.value))
 
 
 VARIABLE = (
@@ -151,7 +155,7 @@ def _format_marker(marker, first=True):
  else:
  return "(" + " ".join(inner) + ")"
  elif isinstance(marker, tuple):
- return '{0} {1} "{2}"'.format(*marker)
+ return '{0} {1} {2}'.format(*marker)
  else:
  return marker
 

tests/unit/test_req.py

@@ -603,3 +603,26 @@ def test_exclusive_environment_markers():
  req_set.add_requirement(eq26)
  req_set.add_requirement(ne26)
  assert req_set.has_requirement('Django')
+
+
+def test_requirement_str():
+ for req_str, req_cannonical_str in (
+ ('pywin32 (>1.0); sys.platform == "win32"',
+ "pywin32>1.0; sys_platform == 'win32'"),
+ ("pywin31; sys.platform == 'win32'",
+ "pywin31; sys_platform == 'win32'"),
+ ("foo != 1.3; platform.machine=='i386'",
+ "foo!=1.3; platform_machine == 'i386'"),
+ ("bar; python_version=='2.4'or python_version==\"2.5\"",
+ "bar; python_version == '2.4' or python_version == '2.5'"),
+ ("bar; ('3.2' <= python_version and python_version <= '3.5')",
+ "bar; '3.2' <= python_version and python_version <= '3.5'"),
+ ("libxslt; 'linux' in sys.platform",
+ "libxslt; 'linux' in sys_platform"),
+ ("foobar; '\"' in sys_platform",
+ "foobar; '\"' in sys_platform"),
+ ("foobar; \"'\" in sys_platform",
+ "foobar; \"'\" in sys_platform"),
+ ):
+ req = Requirement(req_str)
+ assert str(req) == req_cannonical_str