Fixes#6890 by reading from the Windows console input buffer after
stdin has been closed.
Vim defines HAVE_DUP for Windows and does the close-dup dance[1]:
close(0);
dup(2);
which always fails, then falls back to reading from the Windows console
input buffer[2].
[1] e7499ddc33/src/fileio.c (L2397-L2398)
[2] e7499ddc33/src/os_win32.c (L1703-L1714)
* Reading from stdin on Windows is fixed in the same way as it was in
#8267.
* The file_read function was returning without filling the
destination buffer when it was called with a non-blocking file
descriptor.
This fixes an issue with compiles failing in release mode due to shape
having the possibility of being used uninitialized (since the default
case was missing).
Any user can create a directory on root.
Creating a directory on root allows any user to write files within that directory.
Test_recover_root_dir() passes when run locally as a regular user (not admin).
Unset $SHELL so that child nvim use cmd.exe as default shell.
Unset $TERM so that child nvim don't segfault with negative exit code.
sh/bash use TERM=cygwin by default if it is unset.
mintty sets TERM to xterm.
It is hard to say whether it actually is uninitialized, need to go deeper into
regex code. Probably analyzer did not go that far as regmatch for sure would not
be initialized up until calling NFA/DFA engine functions, which is to be done by
pointer.
It appears that transchar() was working under assumption that
`transchar_nonprint()` may be used for multibyte characters while its
documentation stated exact opposite. It was not actually untrue though, except
that longer buffer would be needed then the one stated in documentation. But it
is false now with assert().
The implementation of vim_fgets() differs between Neovim and Vim.
Vim says that it only returns `true` for EOF. But it always returns `true` when
fgets() returns NULL. This happens for EOF _or_ errors.
That probably misguided the author of Neovim's vim_fgets(), which does NOT
return `true` for errors.
Since all the callers of vim_fgets() probably expect it to work as it does in
Vim (and not as it says), it now returns the same values as the Vim
implementation.
Fixes#8227
