[Python-checkins] bpo-32409: Fix regression in activate.bat on international Windows (GH-10295)

[Vinay Sajip]

https://github.com/python/cpython/commit/c64583b6d3e8516a8cd2b5f84fc1e300bfac2206
commit: c64583b6d3e8516a8cd2b5f84fc1e300bfac2206
branch: master
author: samstagern <30337691+samstagern at users.noreply.github.com>
committer: Vinay Sajip <vinay_sajip at yahoo.co.uk>
date: 2018-11-07T16:49:14Z
summary:

bpo-32409: Fix regression in activate.bat on international Windows (GH-10295)

Handle Unicode contents on localised Windows systems when activating a
venv. activate.bat currently breaks on German Windows systems, as chcp.com does
not return a plain number as on English systems, but (arbitrarily) appends a dot at the end
(for example "Aktive Codepage: 850." instead of "Active Codepage: 850"). The
dependency to chcp.com is removed and ctypes is used to get, set and restore the
console output code page. The code page for console input is not changed.

We can't use __VENV_PYTHON__ to find python.exe, since it's UTF-8. cmd.exe decodes
the script using the console output code page.

files:
A Misc/NEWS.d/next/Library/2018-11-02-12-01-00.bpo-32409.MFRX2Q.rst
M Lib/venv/scripts/nt/activate.bat

diff --git a/Lib/venv/scripts/nt/activate.bat b/Lib/venv/scripts/nt/activate.bat
index 126049f495fe..2c81a28ce938 100644
--- a/Lib/venv/scripts/nt/activate.bat
+++ b/Lib/venv/scripts/nt/activate.bat
@@ -1,11 +1,10 @@
 @echo off
 
-rem This file is UTF-8 encoded, so we need to update the current code page while executing it
-for /f "tokens=2 delims=:" %%a in ('"%SystemRoot%\System32\chcp.com"') do (
-    set "_OLD_CODEPAGE=%%a"
-)
+rem This file is UTF-8 encoded, so we need to update the current code page while executing it.
+for /f %%a in ('%~dp0python.exe -Ic "import ctypes; print(ctypes.windll.kernel32.GetConsoleOutputCP())"') do (set "_OLD_CODEPAGE=%%a")
+
 if defined _OLD_CODEPAGE (
-    "%SystemRoot%\System32\chcp.com" 65001 > nul
+    %~dp0python.exe -Ic "import ctypes; ctypes.windll.kernel32.SetConsoleOutputCP(65001)"
 )
 
 set "VIRTUAL_ENV=__VENV_DIR__"
@@ -40,6 +39,6 @@ set "PATH=%VIRTUAL_ENV%\__VENV_BIN_NAME__;%PATH%"
 
 :END
 if defined _OLD_CODEPAGE (
-    "%SystemRoot%\System32\chcp.com" %_OLD_CODEPAGE% > nul
+    %~dp0python.exe -Ic "import ctypes; ctypes.windll.kernel32.SetConsoleOutputCP(%_OLD_CODEPAGE%)"
     set "_OLD_CODEPAGE="
 )
diff --git a/Misc/NEWS.d/next/Library/2018-11-02-12-01-00.bpo-32409.MFRX2Q.rst b/Misc/NEWS.d/next/Library/2018-11-02-12-01-00.bpo-32409.MFRX2Q.rst
new file mode 100644
index 000000000000..9b57c5b89ae5
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2018-11-02-12-01-00.bpo-32409.MFRX2Q.rst
@@ -0,0 +1,2 @@
+Fixed implementation of :file:`activate.bat` to handle Unicode contents on
+localized Windows systems (eg. German). Patch by Martin Bijl.
\ No newline at end of file