Appending text to internal tty may cause vim to hang indefinitely

[julio-b]

Steps to reproduce

1. This works as expected:

vim --clean -c'set bt=nofile | eval ["\e[32mtest\e[m", "\e[33mTEST\e[m"]->repeat(40)->setline(1)' -c 'exe "term NONE"| wincmd j | exe "w >>"..2->term_gettty()'

2. Now repeat the same test with larger text:

vim --clean -c'set bt=nofile | eval ["\e[32mtest\e[m", "\e[33mTEST\e[m"]->repeat(2040)->setline(1)' -c 'exe "term NONE"| wincmd j | exe "w >>"..2->term_gettty()'

Vim completely freezes.

Expected behaviour

The text should be appended to the embedded terminal without errors.

Version of Vim

v9.1.0359

Environment

Terminal: kitty
$TERM: xterm-kitty
OS: Archlinux
shell: bash 5.2.26

Logs and stack traces

There are no logs or errors.
I tracked this as best as i could with gdb/strace, and i think vim hangs up in src/fileio.c:5758. The write syscall never returns for some reason.

Backtrace

#0  0x00007ffff7b741a4 in __GI___libc_write (fd=fd@entry=11, buf=buf@entry=0x555555c74590, 
    nbytes=nbytes@entry=8192) at ../sysdeps/unix/sysv/linux/write.c:26
#1  0x000055555563a8fb in write_eintr (fd=11, buf=buf@entry=0x555555c74590, 
    bufsize=bufsize@entry=8192) at fileio.c:5759
#2  0x00005555557e9a72 in buf_write_bytes (ip=ip@entry=0x7fffffffa870) at bufwrite.c:517
#3  0x00005555557ead1e in buf_write (buf=buf@entry=0x5555558f40d0, fname=<optimized out>, 
    fname@entry=0x555555c6fa30 "/dev/pts/5", sfname=<optimized out>, 
    sfname@entry=0x555555c6f9f4 "/dev/pts/5", start=1, end=<optimized out>, 
    eap=eap@entry=0x7fffffffae00, append=1, forceit=0, reset_changed=1, filtering=0)
    at bufwrite.c:2056
#4  0x0000555555612661 in do_write (eap=0x7fffffffae00) at ex_cmds.c:2093
#5  0x000055555562581e in do_one_cmd (cookie=0x0, fgetline=0x0, cstack=0x7fffffffafb0, 
    flags=3, cmdlinep=0x7fffffffad60) at ex_docmd.c:2620
#6  do_cmdline (cmdline=<optimized out>, fgetline=0x0, cookie=0x0, flags=flags@entry=3)
    at ex_docmd.c:1032
#7  0x00005555555f51ab in ex_execute (eap=0x7fffffffb890) at eval.c:7627
#8  0x000055555562581e in do_one_cmd (cookie=0x0, fgetline=0x0, cstack=0x7fffffffba40, 
    flags=11, cmdlinep=0x7fffffffb7f0) at ex_docmd.c:2620
#9  do_cmdline (cmdline=<optimized out>, fgetline=fgetline@entry=0x0, 
    cookie=cookie@entry=0x0, flags=flags@entry=11) at ex_docmd.c:1032
#10 0x0000555555626c9e in do_cmdline_cmd (cmd=<optimized out>) at ex_docmd.c:626
#11 0x00005555558110de in exe_commands (parmp=0x5555558ea880 <params>) at main.c:3173
#12 vim_main2 () at main.c:790
#13 0x00007ffff7a9dcd0 in __libc_start_call_main (main=main@entry=0x55555559a870 <main>, 
    argc=argc@entry=5, argv=argv@entry=0x7fffffffc278)
    at ../sysdeps/nptl/libc_start_call_main.h:58
#14 0x00007ffff7a9dd8a in __libc_start_main_impl (main=0x55555559a870 <main>, argc=5, 
    argv=0x7fffffffc278, init=<optimized out>, fini=<optimized out>, 
    rtld_fini=<optimized out>, stack_end=0x7fffffffc268) at ../csu/libc-start.c:360
#15 0x000055555559c345 in _start ()

strace logs

Notice how the last syscall only returns after killing the main process.

getpid()                                = 6778
newfstatat(AT_FDCWD, "!pty", 0x7fff20f70b60, 0) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/dev/ptmx", O_RDWR|O_NOCTTY) = 5
rt_sigprocmask(SIG_BLOCK, NULL, [], 8)  = 0
rt_sigaction(SIGCHLD, {sa_handler=SIG_DFL, sa_mask=[], sa_flags=SA_RESTORER|SA_RESTART, sa_restorer=0x7f15b61f8770}, {sa_handler=SIG_DFL, sa_mask=[], sa_flags=0}, 8) = 0
ioctl(5, TIOCGPTN, [3])                 = 0
ioctl(5, TIOCGPTN, [3])                 = 0
ioctl(5, TIOCSPTLCK, [0])               = 0
rt_sigprocmask(SIG_BLOCK, NULL, [], 8)  = 0
rt_sigaction(SIGCHLD, {sa_handler=SIG_DFL, sa_mask=[], sa_flags=SA_RESTORER|SA_RESTART, sa_restorer=0x7f15b61f8770}, {sa_handler=SIG_DFL, sa_mask=[], sa_flags=SA_RESTORER|SA_RESTART, sa_restorer=0x7f15b61f8770}, 8) = 0
openat(AT_FDCWD, "/dev/pts/3", O_RDWR|O_NOCTTY) = 7
close(7)                                = 0
ioctl(5, TCGETS, {c_iflag=ICRNL|IXON, c_oflag=NL0|CR0|TAB0|BS0|VT0|FF0|OPOST|ONLCR, c_cflag=B38400|CS8|CREAD, c_lflag=ISIG|ICANON|ECHO|ECHOE|ECHOK|IEXTEN|ECHOCTL|ECHOKE, ...}) = 0
ioctl(5, TCGETS, {c_iflag=ICRNL|IXON, c_oflag=NL0|CR0|TAB0|BS0|VT0|FF0|OPOST|ONLCR, c_cflag=B38400|CS8|CREAD, c_lflag=ISIG|ICANON|ECHO|ECHOE|ECHOK|IEXTEN|ECHOCTL|ECHOKE, ...}) = 0
ioctl(5, TIOCSWINSZ, {ws_row=24, ws_col=92, ws_xpixel=460, ws_ypixel=240}) = 0
fcntl(5, F_SETFL, O_RDONLY|O_NONBLOCK)  = 0
openat(AT_FDCWD, ".", O_RDONLY)         = 7
fchdir(7)                               = 0
chdir("/dev/pts")                       = 0
getcwd("/dev/pts", 4096)                = 9
fchdir(7)                               = 0
close(7)                                = 0
newfstatat(AT_FDCWD, "/dev/pts/3", {st_mode=S_IFCHR|0620, st_rdev=makedev(0x88, 0x3), ...}, 0) = 0
openat(AT_FDCWD, ".", O_RDONLY)         = 7
fchdir(7)                               = 0
chdir("/dev/pts")                       = 0
getcwd("/dev/pts", 4096)                = 9
fchdir(7)                               = 0
close(7)                                = 0
newfstatat(AT_FDCWD, "/dev/pts/3", {st_mode=S_IFCHR|0620, st_rdev=makedev(0x88, 0x3), ...}, 0) = 0
newfstatat(AT_FDCWD, "/dev/pts/3", {st_mode=S_IFCHR|0620, st_rdev=makedev(0x88, 0x3), ...}, 0) = 0
readlink("/dev/pts/3", 0x7fff20f6fde0, 4095) = -1 EINVAL (Invalid argument)
newfstatat(AT_FDCWD, "/dev/pts/.3.swp", 0x7fff20f70e40, 0) = -1 ENOENT (No such file or directory)
write(1, "\r\"/dev/pts/3\" \33[51;14H\33[K", 25) = 25
newfstatat(AT_FDCWD, "/dev/pts/3", {st_mode=S_IFCHR|0620, st_rdev=makedev(0x88, 0x3), ...}, 0) = 0
newfstatat(AT_FDCWD, "/dev/pts/3", {st_mode=S_IFCHR|0620, st_rdev=makedev(0x88, 0x3), ...}, 0) = 0
openat(AT_FDCWD, "/dev/pts/3", O_WRONLY|O_APPEND) = 7
write(7, "\33[32mtexttexttext"..., 8192) = 8192
write(7, "texttext\n\33[32mtext"..., 8192) = 8192
write(7, "texttexttext"..., 8192) = 1220
--- SIGTERM {si_signo=SIGTERM, si_code=SI_USER, si_pid=6991, si_uid=1000} ---
rt_sigreturn({mask=[]})                 = 1220
write(7, "\n\33[m\33[32mtexttexttext\n"..., 6972) = ?
+++ killed by SIGKILL +++

[ronin49]

so maybe it's linux problem, not vim?)