Allow requirements.txt URLs to have egg= definitions.

docs/requirement-format.txt

@@ -24,6 +24,15 @@ The ``#egg=MyProject`` part is important, because while you can
 install simply given the svn location, the project name is useful in
 other places.
 
+You can also specify the egg name for a non-editable url. This is useful to
+point to HEAD locations on the local filesystem:
+
+    file:///path/to/your/lib/project#egg=MyProject
+
+or relative paths:
+
+    file:../../lib/project#egg=MyProject
+
 If you need to give pip (and by association easy_install) hints
 about where to find a package, you can use the ``-f``
 (``--find-links``) option, like::

pip/index.py

@@ -578,13 +578,9 @@ class Link(object):
 
     @property
     def filename(self):
-        url = self.url
-        url = url.split('#', 1)[0]
-        url = url.split('?', 1)[0]
-        url = url.rstrip('/')
+        url = self.url_fragment
         name = posixpath.basename(url)
-        assert name, (
-            'URL %r produced no filename' % url)
+        assert name, ('URL %r produced no filename' % url)
         return name
 
     @property
@@ -598,6 +594,14 @@ class Link(object):
     def splitext(self):
         return splitext(posixpath.basename(self.path.rstrip('/')))
 
+    @property
+    def url_fragment(self):
+        url = self.url
+        url = url.split('#', 1)[0]
+        url = url.split('?', 1)[0]
+        url = url.rstrip('/')
+        return url
+
     _egg_fragment_re = re.compile(r'#egg=([^&]*)')
 
     @property

pip/req.py

@@ -73,28 +73,34 @@ class InstallRequirement(object):
         """
         url = None
         name = name.strip()
-        req = name
+        req = None
         path = os.path.normpath(os.path.abspath(name))
+        link = None
 
         if is_url(name):
-            url = name
-            ## FIXME: I think getting the requirement here is a bad idea:
-            #req = get_requirement_from_url(url)
-            req = None
+            link = Link(name)
         elif os.path.isdir(path) and (os.path.sep in name or name.startswith('.')):
             if not is_installable_dir(path):
-                raise InstallationError("Directory %r is not installable. File 'setup.py' not found."
-                                        % name)
-            url = path_to_url(name)
-            #req = get_requirement_from_url(url)
-            req = None
+                raise InstallationError("Directory %r is not installable. File 'setup.py' not found.", name)
+            link = Link(path_to_url(name))
         elif is_archive_file(path):
             if not os.path.isfile(path):
-                logger.warn('Requirement %r looks like a filename, but the file does not exist'
-                            % name)
-            url = path_to_url(name)
-            #req = get_requirement_from_url(url)
-            req = None
+                logger.warn('Requirement %r looks like a filename, but the file does not exist', name)
+            link = Link(path_to_url(name))
+
+        # If the line has an egg= definition, but isn't editable, pull the requirement out.
+        # Otherwise, assume the name is the req for the non URL/path/archive case.
+        if link and req is None:
+          url = link.url_fragment
+          req = link.egg_fragment
+
+          # Handle relative file URLs
+          if link.scheme == 'file' and re.search(r'\.\./', url):
+            url = path_to_url(os.path.normpath(os.path.abspath(link.path)))
+
+        else:
+          req = name
+
         return cls(req, comes_from, url=url)
 
     def __str__(self):

tests/test_requirements.py

@@ -1,7 +1,9 @@
 import textwrap
+from pip.backwardcompat import urllib
 from pip.req import Requirements
-from tests.test_pip import reset_env, run_pip, write_file, pyversion
+from tests.test_pip import reset_env, run_pip, write_file, pyversion, here
 from tests.local_repos import local_checkout
+from tests.path import Path
 
 def test_requirements_file():
     """
@@ -22,6 +24,19 @@ def test_requirements_file():
     fn = '%s-%s-py%s.egg-info' % (other_lib_name, other_lib_version, pyversion)
     assert result.files_created[env.site_packages/fn].dir
 
+def test_relative_requirements_file():
+    """
+    Test installing from a requirements file with a relative path with an egg= definition..
+
+    """
+    url = 'file://' + str(urllib.quote(Path(here).abspath + '/packages/../packages/FSPkg') + '#egg=FSPkg').replace('\\', '/')
+    env = reset_env()
+    write_file('file-egg-req.txt', textwrap.dedent("""\
+        %s
+        """ % url))
+    result = run_pip('install', '-vvv', '-r', env.scratch_path / 'file-egg-req.txt')
+    assert (env.site_packages/'FSPkg-0.1dev-py%s.egg-info' % pyversion) in result.files_created, str(result)
+    assert (env.site_packages/'fspkg') in result.files_created, str(result.stdout)
 
 def test_multiple_requirements_files():
     """