Calling cmd.exe in Windows follows a very different pattern from Vim.
The primary difference is that Vim does a nested call to cmd.exe, e.g.
the following call in Vim
system('echo a 2>&1')
spawns the following processes
"C:\Program Files (x86)\Vim\vim80\vimrun" -s C:\Windows\system32\cmd.exe /c (echo a 2^>^&1
^>C:\Users\dummy\AppData\Local\Temp\VIoC169.tmp 2^>^&1)
C:\Windows\system32\cmd.exe /c C:\Windows\system32\cmd.exe /c (echo a 2^>^&1
^>C:\Users\dummy\AppData\Local\Temp\VIo3C6C.tmp 2^>^&1)
C:\Windows\system32\cmd.exe /c (echo a 2>&1
>C:\Users\dummy\AppData\Local\Temp\VIo3C6C.tmp 2>&1)
The escaping with ^ is needed because cmd.exe calls itself and needs to
preserve the special metacharacters for the last call. However in nvim
no nested call is made, system('') spawns a single cmd.exe process.
Setting shellxescape to "" disables escaping with ^.
The previous default for shellxquote=( wrapped any command in
parenthesis, in Vim this is more meaningful due to the use of tempfiles
to store the output and redirection (also see &shellquote). There is
a slight benefit in having the default be empty because some expressions
that run in console will not run within parens e.g. due to unbalanced
double quotes
system('echo "a b')
Disable CommandLineToArgvW-standard quoting for cmd.exe.
libuv assumes spawned processes follow the convention expected by
CommandLineToArgvW(). But cmd.exe is non-conformant, so for cmd.exe:
- With system([]), the caller has full control (and responsibility) to
quote arguments correctly.
- With system(''), shell* options are used.
libuv quoting is disabled if argv[0] is:
- cmd.exe
- cmd
- $COMSPEC resolving to a path with filename cmd.exe
Closes#6329
References #6387
Hope this will make people using feed_command less likely: this hides bugs.
Already found at least two:
1. msgpackparse() will show internal error: hash_add() in case of duplicate
keys, though it will still work correctly. Currently silenced.
2. ttimeoutlen was spelled incorrectly, resulting in option not being set when
expected. Test was still functioning somehow though. Currently fixed.
For now it is full of FIXMEs and tests for incorrect behaviour. Sorted out to
have FIXMEs in one place, commented crashing tests in other and correctly
working tests in the third one.
Additionally
- Rename former tv_get_float to tv_get_float_chk due to name conflict (former
get_tv_float is better suited for being tv_get_float).
- Add E907 error to get_tv_float() and test that it is being raised when
appropriate.
1. When calling writefile(list, fname, []) do not show error message twice.
2. Do not allow file name to be overwritten for writefile([1], 2).
3. Do not show “Can’t open file with an empty name” error after error like
“using Float as a String” when type of the second argument is not correct.
4. Do not give multiple error messages and still continue for code like
`writefile(["test", [], [], [], "tset"])`.
Note that to fix 4. ideally I need tv_check_str_or_nr which is currently present
in two PRs: #6114 and #5119. I would want to avoid copying this function into
a yet another PR.
Ref vim/vim#1476.
