Fix some problems with allowed_eggs_from_site_packages

src/zc/buildout/easy_install.py

@@ -58,7 +58,6 @@ if is_jython:
     import java.lang.System
     jython_os_name = (java.lang.System.getProperties()['os.name']).lower()
 
-
 setuptools_loc = pkg_resources.working_set.find(
     pkg_resources.Requirement.parse('setuptools')
     ).location
@@ -873,7 +872,13 @@ class Installer:
                         dist = best[req.key] = env.best_match(req, ws)
                     except pkg_resources.VersionConflict, err:
                         raise VersionConflict(err, ws)
-                    if dist is None:
+                    if dist is None or (
+                        dist.location in self._site_packages and not
+                        self.allow_site_package_egg(dist.project_name)):
+                        # If we didn't find a distribution in the
+                        # environment, or what we found is from site
+                        # packages and not allowed to be there, try
+                        # again.
                         if destination:
                             logger.debug('Getting required %r', str(req))
                         else:
@@ -1548,15 +1553,15 @@ def _generate_site(dest, working_set, executable, extra_paths=(),
     """
     path = _get_path(working_set, extra_paths)
     site_path = os.path.join(dest, 'site.py')
-    egg_path_string, preamble = _relative_path_and_setup(
-        site_path, path, relative_paths, indent_level=2, omit_os_import=True)
-    if preamble:
-        preamble = '\n'.join(
-            [(line and '    %s' % (line,) or line)
-             for line in preamble.split('\n')])
-    original_path_setup = ''
+    original_path_setup = preamble = ''
     if include_site_packages:
         stdlib, site_paths = _get_system_paths(executable)
+        # We want to make sure that paths from site-packages, such as those
+        # allowed by allowed_eggs_from_site_packages, always come last, or
+        # else site-packages paths may include packages that mask the eggs we
+        # really want.
+        path = [p for p in path if p not in site_paths]
+        # Now we set up the code we need.
         original_path_setup = original_path_snippet % (
             _format_paths((repr(p) for p in site_paths), 2),)
         distribution = working_set.find(
@@ -1570,10 +1575,17 @@ def _generate_site(dest, working_set, executable, extra_paths=(),
                     relative_paths)
             else:
                 location = repr(distribution.location)
-            preamble += namespace_include_site_packages_setup % (location,)
+            preamble = namespace_include_site_packages_setup % (location,)
             original_path_setup = (
                 addsitedir_namespace_originalpackages_snippet +
                 original_path_setup)
+    egg_path_string, relative_preamble = _relative_path_and_setup(
+        site_path, path, relative_paths, indent_level=2, omit_os_import=True)
+    if relative_preamble:
+        relative_preamble = '\n'.join(
+            [(line and '    %s' % (line,) or line)
+             for line in relative_preamble.split('\n')])
+        preamble = relative_preamble + preamble
     addsitepackages_marker = 'def addsitepackages('
     enableusersite_marker = 'ENABLE_USER_SITE = '
     successful_rewrite = False

src/zc/buildout/tests.py

@@ -2255,6 +2255,75 @@ include-site-packages.
 
     """
 
+def allowed_eggs_from_site_packages_dependencies_bugfix():
+    """
+If you specify that a package with a dependency may come from site-packages,
+that doesn't mean that the dependency may come from site-packages.  This
+is a test for a bug fix to verify that this is true.
+
+    >>> py_path, site_packages_path = make_py()
+    >>> create_sample_sys_install(site_packages_path)
+    >>> interpreter_dir = tmpdir('interpreter')
+    >>> interpreter_parts_dir = os.path.join(
+    ...     interpreter_dir, 'parts', 'interpreter')
+    >>> interpreter_bin_dir = os.path.join(interpreter_dir, 'bin')
+    >>> mkdir(interpreter_bin_dir)
+    >>> mkdir(interpreter_dir, 'eggs')
+    >>> mkdir(interpreter_dir, 'parts')
+    >>> mkdir(interpreter_parts_dir)
+    >>> ws = zc.buildout.easy_install.install(
+    ...     ['demo'], join(interpreter_dir, 'eggs'), executable=py_path,
+    ...     links=[link_server], index=link_server+'index/',
+    ...     allowed_eggs_from_site_packages=['demo'])
+    >>> [dist.project_name for dist in ws]
+    ['demo', 'demoneeded']
+    >>> from pprint import pprint
+    >>> pprint([dist.location for dist in ws])
+    ['/executable_buildout/site-packages',
+     '/interpreter/eggs/demoneeded-1.1-pyN.N.egg']
+
+    """
+
+def allowed_eggs_from_site_packages_bug_592524():
+    """
+When we use allowed_eggs_from_site_packages, we need to make sure that the
+site-packages paths are not inserted with the normal egg paths.  They already
+included at the end, and including them along with the normal egg paths will
+possibly mask subsequent egg paths.  This affects interpreters and scripts
+generated by sitepackage_safe_scripts.
+
+Our "py_path" has the "demoneeded" and "demo" packages available.
+
+    >>> py_path, site_packages_path = make_py()
+    >>> create_sample_sys_install(site_packages_path)
+    >>> interpreter_dir = tmpdir('interpreter')
+    >>> interpreter_parts_dir = os.path.join(
+    ...     interpreter_dir, 'parts', 'interpreter')
+    >>> interpreter_bin_dir = os.path.join(interpreter_dir, 'bin')
+    >>> mkdir(interpreter_bin_dir)
+    >>> mkdir(interpreter_dir, 'eggs')
+    >>> mkdir(interpreter_dir, 'parts')
+    >>> mkdir(interpreter_parts_dir)
+    >>> ws = zc.buildout.easy_install.install(
+    ...     ['demo', 'other'], join(interpreter_dir, 'eggs'), executable=py_path,
+    ...     links=[link_server], index=link_server+'index/',
+    ...     allowed_eggs_from_site_packages=['demo'])
+    >>> generated = zc.buildout.easy_install.sitepackage_safe_scripts(
+    ...     interpreter_bin_dir, ws, py_path, interpreter_parts_dir,
+    ...     interpreter='py', include_site_packages=True)
+
+Now we will look at the paths in the site.py we generated.  Notice that the
+site-packages are at the end.  They were not before this bugfix.
+
+    >>> test = 'import pprint, sys; pprint.pprint(sys.path[-4:])'
+    >>> print call_py(join(interpreter_bin_dir, 'py'), test)
+    ['/interpreter/eggs/other-1.0-pyN.N.egg',
+     '/interpreter/eggs/demoneeded-1.1-pyN.N.egg',
+     '/executable_buildout/eggs/setuptools-0.0-pyN.N.egg',
+     '/executable_buildout/site-packages']
+    <BLANKLINE>
+    """
+
 def subprocesses_have_same_environment_by_default():
     """
 The scripts generated by sitepackage_safe_scripts set the PYTHONPATH so that,