Close #20568: install unversioned pip command on Windows

Misc/NEWS

@@ -10,6 +10,9 @@ Release date: 2014-03-09
 Build
 -----
 
+- Issue #20568: The Windows installer now installs the unversioned ``pip``
+  command in addition to the versioned ``pip3`` and ``pip3.4`` commands.
+
 - Issue #20757: The ensurepip helper for the Windows uninstaller now skips
   uninstalling pip (rather than failing) if the user has updated pip to a
   different version from the one bundled with ensurepip.

Tools/msi/msi.py

@@ -420,7 +420,7 @@ def add_ui(db):
 
     compileargs = r'-Wi "[TARGETDIR]Lib\compileall.py" -f -x "bad_coding|badsyntax|site-packages|py2_|lib2to3\\tests|venv\\scripts" "[TARGETDIR]Lib"'
     lib2to3args = r'-c "import lib2to3.pygram, lib2to3.patcomp;lib2to3.patcomp.PatternCompiler()"'
-    updatepipargs = r'-m ensurepip -U'
+    updatepipargs = r'-m ensurepip -U --default-install'
     removepipargs = r'-m ensurepip._uninstall'
     # See "CustomAction Table"
     add_data(db, "CustomAction", [