Don't check installation directory writability and site/.pth setup when

using --editable.

--HG--
branch : setuptools-0.6
extra : convert_revision : svn%3A6015fed2-1504-0410-9fe1-9d1591cc4771/sandbox/branches/setuptools-0.6%4051782

EasyInstall.txt

@@ -1197,6 +1197,9 @@ Release Notes/Change History
  * The ``ez_setup.py`` script now actually works when you put a setuptools
    ``.egg`` alongside it for bootstrapping an offline machine.
 
+ * A writable installation directory on ``sys.path`` is no longer required to
+   download and extract a source distribution using ``--editable``.
+
 0.6c1
  * EasyInstall now includes setuptools version information in the
    ``User-Agent`` string sent to websites it visits.

setuptools/command/easy_install.py

@@ -155,7 +155,7 @@ class easy_install(Command):
                     )
                 else:
                     self.all_site_dirs.append(normalize_path(d))
-        self.check_site_dir()
+        if not self.editable: self.check_site_dir()
         self.index_url = self.index_url or "http://www.python.org/pypi"
         self.shadow_path = self.all_site_dirs[:]
         for path_item in self.install_dir, normalize_path(self.script_dir):
@@ -411,7 +411,7 @@ Please make the appropriate changes for your system and try again.
     def easy_install(self, spec, deps=False):
         tmpdir = tempfile.mkdtemp(prefix="easy_install-")
         download = None
-        self.install_site_py()
+        if not self.editable: self.install_site_py()
 
         try:
             if not isinstance(spec,Requirement):