[msys2-runtime] arguments mangled when passed to cygwin executables

[lazka]

Same problem with Python2 and Python3

import subprocess;print(subprocess.check_output(['echo', '--foo="bar"', '--quux="baz"']).decode())

Prints --foo=\bar" --quux="baz" instead of --foo="bar" --quux="baz"

edit: minimal example ['echo', '"']

This breaks some meson builds when perl scripts are called. For example pango with help2man.

[lazka]

Same problem with the official Python when calling the msys2 echo exe.

[lazka]

Some more. Python uses list2cmdline() to convert the list of arguments to a single argument string. CommandLineToArgvW() gets the original list back, so this looks to me as if Python is doing the right thing here and the error is on the msys/cygwin side of things.

import ctypes
from ctypes import wintypes
from subprocess import list2cmdline

CommandLineToArgvW = ctypes.windll.shell32.CommandLineToArgvW
CommandLineToArgvW.restype = ctypes.POINTER(wintypes.LPWSTR)
CommandLineToArgvW.argtypes = [
    wintypes.LPCWSTR,
    ctypes.POINTER(ctypes.c_int),
]

lpCommandLine = list2cmdline(['echo', '--foo="bar"', '--quux="baz"'])
argc = ctypes.c_int()
argv = CommandLineToArgvW(lpCommandLine, ctypes.byref(argc))
argv = argv[:argc.value]
print(argv)

[lazka]

ok, cygwin bug I guess:

C:\msys64\usr\bin>echo.exe -DFOO=\"BAR\"
-DFOO=\BAR"

Reproduced with upstream cygwin.

[lazka]

I've "filed" a bug: http://cygwin.org/ml/cygwin/2019-06/msg00189.html

[lazka]

Here is a reproducer written in C: https://gist.github.com/lazka/3d828f9ed3bdf6b981eeb5edca65c657

[lazka]

No response on the "bugtracker" :/