- In this implementation, pseudo console is created for each native
console app. Advantages and disadvantages of this implementation
over the previous implementation are as follows.
Advantages:
1) No performance degradation in pty output for cygwin process.
https://cygwin.com/pipermail/cygwin/2020-February/243858.html
2) Free from the problem caused by difference of behaviour of control
sequences between real terminal and pseudo console.
https://cygwin.com/pipermail/cygwin/2019-December/243281.htmlhttps://cygwin.com/pipermail/cygwin/2020-February/243855.html
3) Free from the problem in cgdb and emacs gud.
https://cygwin.com/pipermail/cygwin/2020-January/243601.htmlhttps://cygwin.com/pipermail/cygwin/2020-March/244146.html
4) Redrawing screen on executing native console apps is not necessary.
5) cygwin-console-helper is not necessary for the pseudo console
support.
6) The codes for pseudo console support are much simpler than that
of the previous one.
Disadvantages:
1) The cygwin program which calls console API directly does not work.
2) The apps which use console API cannot be debugged with gdb. This
is because pseudo console is not activated since gdb uses
CreateProcess() rather than exec(). Even with this limitation,
attaching gdb to native apps, in which pseudo console is already
activated, works.
3) Typeahead key inputs are discarded while native console app is
executed. Simirally, typeahead key inputs while cygwin app is
executed are not inherited to native console app.
4) Code page cannot be changed by chcp.com. Acctually, chcp works
itself and changes code page of its own pseudo console. However,
since pseudo console is recreated for another process, it cannot
inherit the code page.
5) system_printf() does not work after stderr is closed. (Same with
cygwin 3.0.7)
6) Startup time of native console apps is about 3 times slower than
previous implemenation.
7) Pseudo console cannot be activated if it is already activated for
another process on same pty.
This should slightly speed up especially path conversions,
given there's one less function call rearranging all function
arguments in registers/stack (and less stack pressure).
For clarity, rename overloaded sys_wcstombs to _sys_wcstombs
and sys_cp_mbstowcs to _sys_mbstowcs.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
- If the cygwin vim is started from a non-cygwin process which is
executed in pseudo console, shift key and ctrl key do not work.
In this case, vim is executed under /dev/cons*. If vim outputs
escape sequence which is not supported by pseudo console, the
escape sequence is leaked into the parent pty. This causes
unexpected results. This patch fixes the issue by discarding
"CSI > Pm m". "OSC 10;? BEL/ST" and "OSC 11;? BEL/ST" are
discarded as well.
Passing a pointer to a local variable to WriteConsoleA is
not actually needed if we're not going to do anything with
what WriteConsoleA would put in there.
For the wpbuf class the pointer argument was made optional,
so it can be just left out; other call places now pass a
NULL pointer instead. The local variables `wn' and `n'
are no unused, so they go away.
Replace direct access to a pair of co-dependent variables
by calls to methods of a class that encapsulates their relation.
Also replace C #define by C++ class constant.
- In xterm compatible mode, "ESC 7" and "ESC 8" do not work properly
in the senario:
1) Execute /bin/ls /bin to fill screen.
2) Sned CSI?1049h to alternate screen.
3) Reduce window size.
4) Send CSI?1049l to resume screen.
5) Send "ESC 7" and "ESC 8".
After sending "ESC 8", the cursor goes to incorrect position. This
patch adds a workaround for this issue.
- This patch fixes the issue that xterm compatible mode for input
is not correctly set/unset in some situation such as:
1) cat is stopped by ctrl-c.
2) The window size is changed in less.
In case 1), request_xterm_mode_input(true) is called in read(),
however, cat is stopped without request_xterm_mode_input(false).
In case 2), less uses longjmp in signal handler, therefore,
corresponding request_xterm_mode_input(false) is not called if
the SIGWINCH signal is sent within read(). With this patch,
InterlockedExchange() is used instead of InterlockedIncrement/
Decrement().
- This patch makes some detailed behaviour of ESC sequences such as
"CSI Ps L" (IL), "CSI Ps M" (DL) and "ESC M" (RI) in xterm mode
match with real xterm.
- In Win10 upto 1809, xterm compatible mode does not have REP
escape sequence which terminfo declares. This patch adds support
for "CSI Ps b" (REP). With this patch, bvi (binary editor) works
normally in Win10 1809. Also, xterm compatible mode does not have
"CSI Pm `" (HPA), "CSI Pm a" (HPR) and "CSI Ps e" (VPR). However,
they do not appear to be declared by terminfo. Therefore, these
have been pending.
- Cygwin console with xterm compatible mode causes problem reported
in https://www.cygwin.com/ml/cygwin-patches/2020-q1/msg00212.html
if background/foreground colors are set to gray/black respectively
in Win10 1903/1909. This is caused by "CSI Ps L" (IL), "CSI Ps M"
(DL) and "ESC M" (RI) control sequences which are broken. This
patch adds a workaround for the issue.
- Accessing shared_console_info before initialization causes access
violation because it is a NULL pointer. The cause of the problem
reported in https://cygwin.com/ml/cygwin/2020-02/msg00197.html is
this NULL pointer access in request_xterm_mode_output() when it is
called from close(). This patch makes sure that shared_console_info
is not NULL before calling request_xterm_mode_output().
A NUL byte in the output stream got accidentally not handled as IGN char
in xterm console mode. The internal mbtowc conversion doesn't handle
embedded NUL values gracefully, it always stops converting at NUL bytes.
This broke the output of strings with embedded NUL bytes.
Fix this by always skipping IGN chars in the "normal char output loop"
and make sure not to move the cursor one position to the right, as in
legacy console mode.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
- If two cygwin programs are executed simultaneousley with pipes
in cmd.exe, xterm compatible mode is accidentally disabled by
the process which ends first. After that, escape sequences are
not handled correctly in the other app. This is the problem 2
reported in https://cygwin.com/ml/cygwin/2020-02/msg00116.html.
This patch fixes the issue. This patch also fixes the problem 3.
For these issues, the timing of setting and unsetting xterm
compatible mode is changed. For read, xterm compatible mode is
enabled only within read() or select() functions. For write, it
is enabled every time write() is called, and restored on close().
- With this patch, foreground color and background color are allowed
to be set simultaneously by 24 bit color escape sequence such as
ESC[38;2;0;0;255;48;2;128;128;0m in legacy console mode.
- The cause of the problem reported in
https://www.cygwin.com/ml/cygwin/2020-01/msg00220.html is that the
chars input before dup() cannot be read from the new file descriptor.
This is because the readahead buffer (rabuf) in the console is newly
created by dup(), and does not inherit from the parent. This patch
fixes the issue.
- The console with 24bit color support has a problem that console
mode is changed if cygwin process is executed in cmd.exe which
started in cygwin shell. For example, cursor keys become not
working if bash -> cmd -> true are executed in this order.
This patch fixes the issue.
- In Win10 1809, the cursor position sometimes goes out of screen
by clear command in console. This seems to be caused by escape
sequence CSI3J (ESC[3J). This happens only for 1809. This patch
is a workaround for the issue.
- Special function keys such as arrow keys or function keys do not
work in ConEmu with cygwin-connector after commit
6a06c6bc8f. This patch fixes the
issue.
fhandler_console::create_invisible_console_workaround() does not use the
lpApplicationName parameter and neglects to quote its command name on
lpCommandLine in the call to CreateProcessW.
Given CreateProcessW's brain-dead method to evaluate the application
path given on the command line, this opens up a security problem if
Cygwin is installed into a path with spaces in it.
Fix this by using the lpApplicationName parameter and quoting of the
application path in the lpCommandLine parameter (used as argv[0] in
the called console helper.
For extended paranoia, make the argument string array big enough to
fit full 64 bit pointer values into it. Handles usually only use
the lower 32 bit, but better safe than sorry.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
- In non-canonical mode, cygwin console returned only one character
even if several keys are typed before read() called. This patch
fixes this behaviour.
- Previously, input and output pipes were switched together between
the traditional pty and the pseudo console. However, for example,
if stdin is redirected to another device, it is better to leave
input pipe traditional pty side even for non-cygwin program. This
patch realizes such behaviour.
- Pseudo console support introduced by commit
169d65a577 has some bugs which
cause mismatch between state variables and real pseudo console
state regarding console attaching and r/w pipe switching. This
patch fixes this issue by redesigning the state management.
- Support pseudo console in PTY. Pseudo console is a new feature
in Windows 10 1809, which provides console APIs on virtual
terminal. With this patch, native console applications can work
in PTYs such as mintty, ssh, gnu screen or tmux.
- If screen is alternated on console, cursor position is not restored
correctly in the case of xterm compatible mode is enabled. For example,
the shell prompt is shown at incorrect position after using vim.
This patch fixes this problem.
- The horizontal tab positions are broken after resizing console window.
This seems to be a bug of xterm compatible mode of windows console.
This workaround fixes this problem.
- After 24 bit color support patch, arrow keys and function keys
do not work properly in native console applications if they
are started in cygwin console. This patch fixes this issue.
- Add 24 bit color support using xterm compatibility mode in
Windows 10 1703 or later.
- Add fake 24 bit color support for legacy console, which uses
the nearest color from 16 system colors.
Takashi Yano via Cygwin-patches
Takashi Yano
Corinna Vinschen
Hans-Bernhard Broeker