[BUG] Windows Terminal `keep pipe:y` about kakoune HOT 10 CLOSED

When Kakoune initialises a terminal, it asks the terminal if it supports mode 2026 (output synchronisation):

\033[?2026$p

The terminal is supposed to respond with "I've never heard of that mode", "yes, and it's currently enabled", or "yes, and it's currently disabled":

\033[?2026;0$y  // never heard of it
\033[?2026;1$y  // enabled
\033[?2026;2$y  // disabled

It seems your terminal is instead sending:

\033[0$y

...which is vaguely like a query response, but I can't see a situation where a terminal should send a response like that.

Here's a command that sends all the control sequences Kakoune sends at startup, then

reset; printf '\033[?1049h\033[?1004h\033[>4;1m\033[>5u\033[22t\033[?25l\033=\033[?2026$p\033[?2004h'; read

If you paste that command into a terminal then press Enter twice, it should clear the screen and then you'll see whatever the terminal sends back, which I expect will look something like this:

^[[I^[[0$y

Is that what happens?

from kakoune.

Can confirm the same here. Doesn't happen in tmux, which is probably to be expected.

from kakoune.

As the Microsoft Terminal issue suggests, a control-sequence sent by the terminal to Kakoune is being interpreted as keys. If you can reproduce this, try :set global debug keys before hitting <c-z>, and then when you bring Kakoune back, if the problem reproduces, go check the *debug* buffer and see what keys have been pressed. It would be interesting to know if it's always the same bytes being misinterpreted as keys (meaning, possibly a problem in Kakoune's input state machine) or if it's sometimes different (meaning, the input stream being split across packets, preventing Kakoune from detecting them as a single control sequence).

from kakoune.

I seem to be always getting the same keys when it reproduces

Client 'client0' got key '<a-[>'
Client 'client0' got key '0'
Client 'client0' got key '$'
Client 'client0' got key 'y'

and nothing when it does not reproduce

from kakoune.

This also happens if I open a second client

# First shell
kak -s myproject

# Second shell
kak -c myproject
# keep pipe:y

from kakoune.

tmux and command prompt send nothing.

Terminal sends

^[[?2026;0$y

from kakoune.

You said originally that the problem reproduces 50% of the time in Kakoune - when you run the printf command, does it always respond ^[[?2026;0$y or just some of the time?

from kakoune.

Your printf command has returned the same thing every time I tried it. However, the response very slow, and there may be a timing problem.

If I hit <enter> before the text appears then I get 2026;0$y in my terminal prompt (with ^[[?2026;0$y in the line above).

If I hit enter twice (as instructed) this is what I get

^[[?2026;0$y
$ 2026;0$y                 # first $ here is the shell prompt

I'm using the starship prompt (the problem was reproducing before I installed it), without that I get

                          # empty line
$ 2026;0$y                # first $ here is the shell prompt

It also makes the cursor disappear, and causes the terminal to make a notification sound when navigated away from, and to.

from kakoune.

I've seen problems from the startup query for terminal synchronisation support too. In my case, it was over a networked serial console, whose slowness can break atomic read() of escape sequences by kakoune. (Interestingly, this is the only breakage I experience in practice with kak on a slow serial console.)

Unfortunately, disabling sync support with

set-option -add global ui_options terminal_synchronized=false

in kakrc doesn't stop the query being sent, so Tom can't just do that to work around it.

For my own build, I have a local patch

diff --git a/src/terminal_ui.cc b/src/terminal_ui.cc
index 86f7d09..71dedb1 100644
--- a/src/terminal_ui.cc
+++ b/src/terminal_ui.cc
@@ -1485,7 +1485,6 @@ void TerminalUI::setup_terminal()
         "\033[22t"    // save the current window title
         "\033[?25l"   // hide cursor
         "\033="       // set application keypad mode, so the keypad keys send unique codes
-        "\033[?2026$p" // query support for synchronize output
         "\033[?2004h" // force enable bracketed-paste events
     );
 }
@@ -1555,6 +1554,10 @@ void TerminalUI::set_ui_options(const Options& options)
     auto synchronized = find("terminal_synchronized").map(to_bool);
     m_synchronized.set = (bool)synchronized;
     m_synchronized.requested = synchronized.value_or(false);
+    if (not m_synchronized.queried and not m_synchronized.set) {
+        write(STDOUT_FILENO, "\033[?2026$p");
+        m_synchronized.queried = true;
+    }

     m_shift_function_key = find("terminal_shift_function_key").map(str_to_int_ifp).value_or(default_shift_function_key);

diff --git a/src/terminal_ui.hh b/src/terminal_ui.hh
index e1a9633..774b436 100644
--- a/src/terminal_ui.hh
+++ b/src/terminal_ui.hh
@@ -158,6 +158,7 @@ private:

     struct Synchronized
     {
+        bool queried : 1;
         bool supported : 1;
         bool set : 1;
         bool requested : 1;

to skip the query when I've explicitly disabled support. Possibly worth sending upstream if others are seeing problems too - I assumed I was the only one who used kakoune in a weird enough niche that it could cause issues.

from kakoune.

This is no longer reproducing for me anymore. Windows Terminal patched?

from kakoune.