Merge Pull Request #144

3 files changed, 109 insertions, 15 deletions

diff --git a/pkg_resources/__init__.py b/pkg_resources/__init__.py
index 0c024f1b..46f09a2d 100644
--- a/pkg_resources/__init__.py
+++ b/pkg_resources/__init__.py
@@ -2473,6 +2473,18 @@ def _remove_md5_fragment(location):
     return location
 
 
+def _version_from_file(lines):
+    """
+    Given an iterable of lines from a Metadata file, return
+    the value of the Version field, if present, or None otherwise.
+    """
+    is_version_line = lambda line: line.lower().startswith('version:')
+    version_lines = filter(is_version_line, lines)
+    line = next(iter(version_lines), '')
+    _, _, value = line.partition(':')
+    return safe_version(value.strip()) or None
+
+
 class Distribution(object):
     """Wrap an actual or potential sys.path entry w/metadata"""
     PKG_INFO = 'PKG-INFO'
@@ -2490,22 +2502,29 @@ class Distribution(object):
         self._provider = metadata or empty_provider
 
     @classmethod
-    def from_location(cls, location, basename, metadata=None,**kw):
+    def from_location(cls, location, basename, metadata=None, **kw):
         project_name, version, py_version, platform = [None]*4
+        dist_path = os.path.join(location, basename)
         basename, ext = os.path.splitext(basename)
         if ext.lower() in _distributionImpl:
-            # .dist-info gets much metadata differently
+            cls = _distributionImpl[ext.lower()]
+
             match = EGG_NAME(basename)
             if match:
                 project_name, version, py_version, platform = match.group(
-                    'name','ver','pyver','plat'
+                    'name', 'ver', 'pyver', 'plat'
                 )
-            cls = _distributionImpl[ext.lower()]
+
+            version = cls._version_from_metadata(dist_path) or version
         return cls(
             location, metadata, project_name=project_name, version=version,
             py_version=py_version, platform=platform, **kw
         )
 
+    @staticmethod
+    def _version_from_metadata(dist_path):
+        pass
+
     @property
     def hashcmp(self):
         return (
@@ -2591,13 +2610,11 @@ class Distribution(object):
         try:
             return self._version
         except AttributeError:
-            for line in self._get_metadata(self.PKG_INFO):
-                if line.lower().startswith('version:'):
-                    self._version = safe_version(line.split(':',1)[1].strip())
-                    return self._version
-            else:
+            version = _version_from_file(self._get_metadata(self.PKG_INFO))
+            if version is None:
                 tmpl = "Missing 'Version:' header and/or %s file"
                 raise ValueError(tmpl % self.PKG_INFO, self)
+            return version
 
     @property
     def _dep_map(self):
@@ -2802,6 +2819,30 @@ class Distribution(object):
         return [dep for dep in self._dep_map if dep]
 
 
+class EggInfoDistribution(Distribution):
+
+    @staticmethod
+    def _version_from_metadata(dist_path):
+        """
+        Packages installed by distutils (e.g. numpy or scipy),
+        which uses an old safe_version, and so
+        their version numbers can get mangled when
+        converted to filenames (e.g., 1.11.0.dev0+2329eae to
+        1.11.0.dev0_2329eae). These distributions will not be
+        parsed properly
+        downstream by Distribution and safe_version, so
+        take an extra step and try to get the version number from
+        the metadata file itself instead of the filename.
+        """
+        if not os.path.isfile(dist_path):
+            return
+        try:
+            with open(dist_path) as strm:
+                return _version_from_file(strm)
+        except IOError:
+            pass
+
+
 class DistInfoDistribution(Distribution):
     """Wrap an actual or potential sys.path entry w/metadata, .dist-info style"""
     PKG_INFO = 'METADATA'
@@ -2867,7 +2908,7 @@ class DistInfoDistribution(Distribution):
 
 _distributionImpl = {
     '.egg': Distribution,
-    '.egg-info': Distribution,
+    '.egg-info': EggInfoDistribution,
     '.dist-info': DistInfoDistribution,
     }
 
diff --git a/pkg_resources/tests/test_pkg_resources.py b/pkg_resources/tests/test_pkg_resources.py
index 564d7cec..0a03dd93 100644
--- a/pkg_resources/tests/test_pkg_resources.py
+++ b/pkg_resources/tests/test_pkg_resources.py
@@ -5,9 +5,15 @@ import zipfile
 import datetime
 import time
 import subprocess
+import stat
+import distutils.dist
+import distutils.command.install_egg_info
+
+import pytest
 
 import pkg_resources
 
+
 try:
     unicode
 except NameError:
@@ -109,3 +115,49 @@ class TestIndependence:
         )
         cmd = [sys.executable, '-c', '; '.join(lines)]
         subprocess.check_call(cmd)
+
+
+
+class TestDeepVersionLookupDistutils(object):
+
+    @pytest.fixture
+    def env(self, tmpdir):
+        """
+        Create a package environment, similar to a virtualenv,
+        in which packages are installed.
+        """
+        class Environment(str):
+            pass
+
+        env = Environment(tmpdir)
+        tmpdir.chmod(stat.S_IRWXU)
+        subs = 'home', 'lib', 'scripts', 'data', 'egg-base'
+        env.paths = dict(
+            (dirname, str(tmpdir / dirname))
+            for dirname in subs
+        )
+        list(map(os.mkdir, env.paths.values()))
+        return env
+
+    def create_foo_pkg(self, env, version):
+        """
+        Create a foo package installed (distutils-style) to env.paths['lib']
+        as version.
+        """
+        attrs = dict(name='foo', version=version)
+        dist = distutils.dist.Distribution(attrs)
+        iei_cmd = distutils.command.install_egg_info.install_egg_info(dist)
+        iei_cmd.initialize_options()
+        iei_cmd.install_dir = env.paths['lib']
+        iei_cmd.finalize_options()
+        iei_cmd.run()
+
+    def test_version_resolved_from_egg_info(self, env):
+        version = '1.11.0.dev0+2329eae'
+        self.create_foo_pkg(env, version)
+
+        # this requirement parsing will raise a VersionConflict unless the
+        # .egg-info file is parsed (see #419 on BitBucket)
+        req = pkg_resources.Requirement.parse('foo>=1.9')
+        dist = pkg_resources.WorkingSet([env.paths['lib']]).find(req)
+        assert dist.version == version
diff --git a/setuptools/tests/test_egg_info.py b/setuptools/tests/test_egg_info.py
index a1caf9fd..645c379c 100644
--- a/setuptools/tests/test_egg_info.py
+++ b/setuptools/tests/test_egg_info.py
@@ -8,7 +8,11 @@ from .textwrap import DALS
 from . import contexts
 
 
-class TestEggInfo:
+class Environment(str):
+    pass
+
+
+class TestEggInfo(object):
 
     setup_script = DALS("""
         from setuptools import setup
@@ -33,8 +37,6 @@ class TestEggInfo:
 
     @pytest.yield_fixture
     def env(self):
-        class Environment(str): pass
-
         with contexts.tempdir(prefix='setuptools-test.') as env_dir:
             env = Environment(env_dir)
             os.chmod(env_dir, stat.S_IRWXU)
@@ -49,8 +51,7 @@ class TestEggInfo:
                 f.write(DALS("""
                     [egg_info]
                     egg-base = %(egg-base)s
-                    """ % env.paths
-                ))
+                    """ % env.paths))
             yield env
 
     def test_egg_base_installed_egg_info(self, tmpdir_cwd, env):