3 files changed, 58 insertions, 10 deletions
diff --git a/setuptools/command/develop.py b/setuptools/command/develop.py
index 368b64fe..5ae25d71 100755
--- a/setuptools/command/develop.py
+++ b/setuptools/command/develop.py
@@ -167,3 +167,30 @@ class develop(easy_install):
             script_text = f.read()
             f.close()
             self.install_script(dist, script_name, script_text, script_path)
+
+    def install_wrapper_scripts(self, dist):
+        dist = VersionlessRequirement(dist)
+        return easy_install.install_wrapper_scripts(self, dist)
+
+
+class VersionlessRequirement(object):
+    """
+    Adapt a pkg_resources.Distribution to simply return the project
+    name as the 'requirement' so that scripts will work across
+    multiple versions.
+
+    >>> dist = Distribution(project_name='foo', version='1.0')
+    >>> str(dist.as_requirement())
+    'foo==1.0'
+    >>> adapted_dist = VersionlessRequirement(dist)
+    >>> str(adapted_dist.as_requirement())
+    'foo'
+    """
+    def __init__(self, dist):
+        self.__dist = dist
+
+    def __getattr__(self, name):
+        return getattr(self.__dist, name)
+
+    def as_requirement(self):
+        return self.project_name
diff --git a/setuptools/command/easy_install.py b/setuptools/command/easy_install.py
index 45d180bb..9e9c5e54 100755
--- a/setuptools/command/easy_install.py
+++ b/setuptools/command/easy_install.py
@@ -20,6 +20,7 @@ from distutils.errors import DistutilsArgError, DistutilsOptionError, \
 from distutils.command.install import INSTALL_SCHEMES, SCHEME_KEYS
 from distutils import log, dir_util
 from distutils.command.build_scripts import first_line_re
+from distutils.spawn import find_executable
 import sys
 import os
 import zipimport
@@ -760,9 +761,10 @@ class easy_install(Command):
         return dst
 
     def install_wrapper_scripts(self, dist):
-        if not self.exclude_scripts:
-            for args in ScriptWriter.best().get_args(dist):
-                self.write_script(*args)
+        if self.exclude_scripts:
+            return
+        for args in ScriptWriter.best().get_args(dist):
+            self.write_script(*args)
 
     def install_script(self, dist, script_name, script_text, dev_path=None):
         """Generate a legacy script wrapper and install it"""
@@ -2125,8 +2127,8 @@ class WindowsScriptWriter(ScriptWriter):
         blockers = [name + x for x in old]
         yield name + ext, header + script_text, 't', blockers
 
-    @staticmethod
-    def _adjust_header(type_, orig_header):
+    @classmethod
+    def _adjust_header(cls, type_, orig_header):
         """
         Make sure 'pythonw' is used for gui and and 'python' is used for
         console (regardless of what sys.executable is).
@@ -2137,11 +2139,19 @@ class WindowsScriptWriter(ScriptWriter):
             pattern, repl = repl, pattern
         pattern_ob = re.compile(re.escape(pattern), re.IGNORECASE)
         new_header = pattern_ob.sub(string=orig_header, repl=repl)
+        return new_header if cls._use_header(new_header) else orig_header
+
+    @staticmethod
+    def _use_header(new_header):
+        """
+        Should _adjust_header use the replaced header?
+
+        On non-windows systems, always use. On
+        Windows systems, only use the replaced header if it resolves
+        to an executable on the system.
+        """
         clean_header = new_header[2:-1].strip('"')
-        if sys.platform == 'win32' and not os.path.exists(clean_header):
-            # the adjusted version doesn't exist, so return the original
-            return orig_header
-        return new_header
+        return sys.platform != 'win32' or find_executable(clean_header)
 
 
 class WindowsExecutableLauncherWriter(WindowsScriptWriter):
diff --git a/setuptools/command/test.py b/setuptools/command/test.py
index 160e21c9..c26f5fc9 100644
--- a/setuptools/command/test.py
+++ b/setuptools/command/test.py
@@ -41,6 +41,17 @@ class ScanningLoader(TestLoader):
             return tests[0]  # don't create a nested suite for only one return
 
 
+# adapted from jaraco.classes.properties:NonDataProperty
+class NonDataProperty(object):
+    def __init__(self, fget):
+        self.fget = fget
+
+    def __get__(self, obj, objtype=None):
+        if obj is None:
+            return self
+        return self.fget(obj)
+
+
 class test(Command):
     """Command to run unit tests after in-place build"""
 
@@ -78,7 +89,7 @@ class test(Command):
         if self.test_runner is None:
             self.test_runner = getattr(self.distribution, 'test_runner', None)
 
-    @property
+    @NonDataProperty
     def test_args(self):
         return list(self._test_args())