Explicitly quote strings rather than relying on repr. Fixes #477.

CHANGES.txt

@@ -9,6 +9,9 @@ CHANGES
 
 * Issue #476: Cast version to string (using default encoding)
   to avoid creating Unicode types on Python 2 clients.
+* Issue #477: In Powershell downloader, use explicit rendering
+  of strings, rather than rely on ``repr``, which can be
+  incorrect (especially on Python 2).
 
 ----
 19.1

ez_setup.py

@@ -225,7 +225,7 @@ def download_file_powershell(url, target):
     ps_cmd = (
         "[System.Net.WebRequest]::DefaultWebProxy.Credentials = "
         "[System.Net.CredentialCache]::DefaultCredentials; "
-        "(new-object System.Net.WebClient).DownloadFile(%(url)r, %(target)r)"
+        '(new-object System.Net.WebClient).DownloadFile("%(url)s", "%(target)s")'
         % vars()
     )
     cmd = [