zsh: make zpty module work

[SquallATF]

make zsh/zpty work with msys2, and can pass most mafredri/zsh-async#26 test.

    master = movefd(master);
    if (master == -1) {
	zerrnam(nam, "cannot duplicate fd %d: %e", master, errno);
	scriptname = oscriptname;
	ineval = oineval;
	return 1;
    }

Since cygwin uses two threads to process the pseudoterminal master device, zpty calls the movefd method to move the file description of the master device, and cygwin disposed the original fhandler_pty_master object, which causes the process thread to run incorrectly. here simply disable the zpty move the master device file descriptor untill cygwin upstream fix this issue.

• zpty error strace

   30 27794711 [main] zsh 1918 fhandler_pty_master::cleanup: /dev/ptmx closing master, usecount 0
   43 27794754 [main] zsh 1918 fhandler_pty_master::close: closing from_master(0x310)/from_master_cyg(0x310)/to_master(0x264)/to_master_cyg(0x31C) since we own them(0)
   38 27794792 [main] zsh 1918 fhandler_pty_master::close: (2420): pty output_mutex (0x1F8): waiting -1 ms
   37 27794829 [main] zsh 1918 fhandler_pty_master::close: (2420): pty output_mutex: acquired
   71 27794900 [ptym] zsh 1918 fhandler_pty_master::pty_master_thread: ReadFile, Win32 error 6
   34 27794934 [ptym] zsh 1918 fhandler_pty_master::pty_master_thread: Reply: from 0x0, to 0x0, error 6
   37 27794971 [ptym] zsh 1918 fhandler_pty_master::pty_master_thread: WriteFile, Win32 error 6
   37 27795008 [ptym] zsh 1918 fhandler_pty_master::pty_master_thread: DisconnectNamedPipe, Win32 error 6
   39 27795047 [ptym] zsh 1918 fhandler_pty_master::pty_master_thread: Leaving

• zsh-async test log

=== RUN   test__async_job_multiple_commands
--- PASS: test__async_job_multiple_commands (0.08s)
=== RUN   test__async_job_print_hi
--- PASS: test__async_job_print_hi (0.07s)
=== RUN   test__async_job_stderr
--- PASS: test__async_job_stderr (0.07s)
=== RUN   test__async_job_wait_for_token
--- PASS: test__async_job_wait_for_token (0.19s)
=== RUN   test_all_options
--- FAIL: test_all_options (15.05s)
        ./async_test.zsh:517: timed out
=== RUN   test_async_flush_jobs
--- PASS: test_async_flush_jobs (0.63s)
=== RUN   test_async_job_error_and_nonzero_exit
--- PASS: test_async_job_error_and_nonzero_exit (0.24s)
=== RUN   test_async_job_git_status
--- PASS: test_async_job_git_status (0.43s)
=== RUN   test_async_job_keeps_nulls
--- PASS: test_async_job_keeps_nulls (0.21s)
=== RUN   test_async_job_multiple_arguments_and_spaces
--- PASS: test_async_job_multiple_arguments_and_spaces (0.27s)
=== RUN   test_async_job_multiple_commands_in_multiline_string
--- PASS: test_async_job_multiple_commands_in_multiline_string (0.22s)
=== RUN   test_async_job_print_matches_input_exactly
--- PASS: test_async_job_print_matches_input_exactly (0.21s)
=== RUN   test_async_job_unique_worker
--- PASS: test_async_job_unique_worker (0.49s)
=== RUN   test_async_job_with_rc_expand_param
--- PASS: test_async_job_with_rc_expand_param (0.19s)
=== RUN   test_async_process_results
--- PASS: test_async_process_results (0.25s)
=== RUN   test_async_process_results_stress
--- FAIL: test_async_process_results_stress (9.13s)
        ./async_test.zsh:182: timed out after 5s
        ./async_test.zsh:183: wanted 20 results, got 14
=== RUN   test_async_start_stop_worker
--- PASS: test_async_start_stop_worker (0.06s)
=== RUN   test_async_worker_notify_sigwinch
--- PASS: test_async_worker_notify_sigwinch (2.44s)
=== RUN   test_async_worker_survives_termination_of_other_worker
--- PASS: test_async_worker_survives_termination_of_other_worker (0.15s)
=== RUN   test_async_worker_update_pwd
--- PASS: test_async_worker_update_pwd (0.33s)
=== RUN   test_async_worker_update_pwd_and_env
--- PASS: test_async_worker_update_pwd_and_env (0.36s)
=== RUN   test_zle_watcher
--- SKIP: test_zle_watcher (0.01s)
        ./async_test.zsh:596: Test is not reliable on zsh 5.0.X
FAIL
exit code 1
FAIL    ./async_test.zsh        31.139s

[lazka]

Is there any upstream issue for this (zsh or cygwin)?

[SquallATF]

There is a cygwin upstream issue but patched zpty to avoid this issue.
zpty invoke movefd will dup and close original fd of /dev/ptmx and cause the fhandler_pty_master object to be recycled, which will damage pty_master_thread and pty_master_fwd_thread threads on that object.

Here is a poc to reproduce cygwin issue, program will hang when close(mfd) at last .

#define _GNU_SOURCE 1
#include <stdlib.h>
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>

int main() {
  static char *name;
  static int mfd, sfd;
  if ((mfd = posix_openpt(O_RDWR|O_NOCTTY)) < 0) {
    printf("posix_openpt failed %d\n", mfd);
    return 1;
  }

  if (grantpt(mfd) || unlockpt(mfd) || !(name = ptsname(mfd))) {
    printf("some failed\n");
    close(mfd);
    return 1;
  }
  int fd;
  if((fd = dup(mfd)) < 0) {
    printf("dup failed %d\n", fd);
    return 1;
  }
  close(mfd);
  mfd = fd;
  if ((sfd = open(name, O_RDWR)) < 0) {
    printf("open %s failed\n", name);
    return 1;
  }

  printf("before close mfd %d\n", mfd);
  close(mfd);
  printf("after close mfd %d\n", mfd);
  close(sfd);  
  printf("before close sfd %d\n", sfd);

  return 0;
}