Problem: Terminal buffers are not refreshed when processing keys that
trigger partial mappings.
Solution: Process due terminal refreshes before redrawing.
Problem: Terminal doesn't detect if the PTY process is suspended or
offer a convenient way for the user to resume the process.
Solution: Detect suspended PTY process on SIGCHLD and show virtual text
"[Process suspended]" at the bottom-left. Resume the process
when the user presses a key.
Problem:
restart hangs when nvim was started with stdin input, "-" marker stays
in v:argv, causing the restarted instance to block reading from stdin.
Solution:
filter out the "-" argument when rebuilding v:argv during restart.
Stdin content is ephemeral and shouldn't be re-read after restart.
Problem: Terminal scrollback may be wrong when increasing height after
outputting lines with full scrollback.
Solution: Ensure enough number of scrollback lines have been deleted.
Problem: Changing terminal height immediately after outputting lines
may lead to wrong scrollback.
Solution: Insert pending scrollback lines before the old window height.
Problem: Wrong scrollback when passing a buffer with many lines to
nvim_open_term().
Solution: Delete all buffer lines before opening the terminal.
I tried to use buf_clear(), but it crashes inside deleted_lines_mark(),
so I'll just use deleted_lines_buf() for now. The behavior of marks can
be decided later.
Problem: heap use-after-free if OptionSet autocommands from setting a terminal's
&buftype wipe the buffer.
Solution: set b_locked during OptionSet for &buftype.
Problem: Terminal doesn't handle ED 3 (clear scrollback) properly.
Solution: Add vterm callback for sb_clear().
Also fix another problem that scrollback lines may be duplicated when
pushing to scrollback immediately after reducing window height, as can
be seen in the changes to test/functional/terminal/window_spec.lua.
Problem: TermResponse deferred due to blocked autocommands lacks "data" payload.
Also, it may not fire if a new v:termresponse reuses the same string address.
Solution: add it. Use the value of v:termresponse for "data.sequence". Replace
pointer comparisons with a flag.
The removal of "old_termresponse" comparisons is required to pass the test on
the CI, or locally for me when compiled in RelWithDebInfo.
Problem: if buf_free_all autocommands open a terminal, it will remain open after
the buffer is freed.
Solution: close terminals again later, this time while blocking autocommands.
Did consider terminal_open checking stuff like b_locked_split instead, but
that's set during BufHidden, etc., which doesn't mean the buffer's being wiped.
Problem: close_buffer autocmds may switch buffers at the last moment when
closing a window, causing terminal_check_size to prefer the size of a closed
window, or TabClosed to set an old <abuf>.
Solution: use the actual last buffer, similar to what TabClosed did before.
NOTE: If buffer was unloaded/deleted (not wiped), then TabClosed's <abuf> may
not use it. (w_buffer = NULL) Maybe odd, but it's how it worked before anyhow.
Relies on close_buffer reliably setting w_buffer to NULL if freed, otherwise
buf_valid is better. Only concern I see is if the window wasn't in the window
list after closing the buffer (close_buffer won't set it to NULL then), but then
win_close{_othertab} should've returned earlier.
Problem: terminal's size may not update after one of its windows close.
Solution: call terminal_check_size after closing a window.
Disable test for Windows, as for some reason it only shows a few lines...
Problem: windows may scroll horizontally upon resize using the old terminal
size, which may be unnecessary and cause the content to be partially out-of-view.
Solution: reset the horizontal scroll after resizing.
Problem:
Recombining composing chars in terminal doesn't work at right edge.
Solution:
Check for the case where printing the previous char didn't advance the
cursor. Reset at_phantom when returning to combine_pos.
Problem: 0x08 is treated as Backspace instead of Ctrl-H on Windows.
Solution: Treat 0x7f as Backspace if VT input is enabled, so that 0x08
is treated as Ctrl-H.
Ref: https://github.com/microsoft/terminal/issues/4949
Problem:
On Windows, writing to a pipe doesn't work if the pipe isn't connected
yet. This causes an RPC request to a session newly created by connect()
to hang, as it's waiting for a response to a request that never reaches
the server.
Solution:
Wait for uv.pipe_connect() callback to be called when using connect().
Problem: Wrong terminal scrollback if BufFile* autocommand drains PTY
output but doesn't process the pending refresh.
Solution: Refresh scrollback before refreshing screen in terminal_open()
if scrollback has been allocated.
Problem: Terminal loses output if a BufFilePre or BufFilePost autocmd
polls for events.
Solution: Rename the buffer after allocating the terminal instance. Also
fix buffer getting wrong name if BufFilePre uses NameBuff.
Usually, terminal_close() calls refresh_terminal(), which allocates the
scrollback buffer, and term_may_alloc_scrollback() in terminal_open()
won't dereference the buffer. However, refresh_terminal() is not called
during Nvim exit, in which case a heap-use-after-free may happen if
TermOpen wipes buffer. Check for non-NULL buf_handle to avoid that.
Problem: When TermOpen polls for enough events to use the scrollback
buffer, scrollback is lost until the next terminal refresh.
Solution: Allocate the scrollback buffer when it's needed.
Problem: :edit and :enew may reuse a 1-line terminal buffer, causing
the new buffer to still be a terminal buffer.
Solution: Don't reuse a terminal buffer, as it's not reused when it has
more than 1 line.
After this change close_buffer() is the only place where buf_freeall()
can be called on a terminal buffer, so move the buf_close_terminal()
call into buf_freeall() to save some code. Furthermore, closing the
terminal in buf_freeall() is probably more correct anyway, as it is
"things allocated for a buffer that are related to the file".
Also, remove the useless check for on_detach callbacks deleting buffer.
Even if b_locked fails to prevent that, the crash will happen at the end
of buf_updates_unload() first. On the other hand, many other call sites
of buf_updates_unload() and other buffer_updates_* functions don't set
b_locked, which may be a problem as well...
Problem: Calling termopen() or nvim_open_term() on a buffer with an
existing terminal leads to two terminals writing to the same
buffer if the terminal job is still running, or memory leak
if the terminal job has exited.
Solution: Close the terminal if the terminal job has exited, otherwise
report an error. For nvim_open_term() also don't write a
closed terminal's buffer content to the PTY.
Problem: Crash when a terminal receives OSC 2 just after closing its
buffer but before terminal job exits.
Solution: Remove FUNC_ATTR_NONNULL_ALL from buf_set_term_title() and
check for NULL.
Problem: Destroying a terminal with pending TermRequest leads to
heap-use-after-free when processing TermRequest afterwards.
Solution: Store the buffer handle instead of the Terminal pointer in the
pending TermRequest event, and don't emit TermRequest if the
terminal is already closed.
Problem: When switching to another terminal buffer in Terminal mode,
usually Nvim stays in Terminal mode, but leaves Terminal mode
if the old terminal buffer was deleted.
Solution: Don't always leave Terminal mode when active terminal buffer
is deleted. Instead let terminal_check_focus() decide that.
Problem:
Terminals should respond with the terminator (either BEL or ST) used in
the query so that clients can reliably parse the responses. The
`TermRequest` autocmd used to handle background color requests in the
terminal does not have access to the original sequence terminator, so it
always uses BEL. #37018
Solution:
Update vterm parsing to include the terminator type, then forward this
data into the emitted `TermRequest` events for OSC/DCS/APC sequences.
Update the foreground/background `TermRequest` callback to use the same
terminator as the original request.
Details:
I didn't add the terminator to the `TermResponse` event. However, I
assume the `TermResponse` event doesn't care about the terminator
because the sequence is already parsed. I also didn't update any of the
functions in `src/nvim/vterm/state.c` that write out responses. It
looked like those all pretty much used ST, and it would be a much larger
set of changes. In that same file, there's also logic for 8 bit ST
sequences, but from what I can tell, 8 bit doesn't really work (see `:h
xterm-8bit`), so I didn't use the 8 bit ST at all.
Problem:
Every CI log has a lot of noise at the end, which makes it harder to
find relevant test failures:
Running tests from test/functional/terminal/tui_spec.lua
...
T5831 TUI bg color queries the terminal for background color:
T5832 TUI bg color triggers OptionSet from automatic background processing:
T5833 TUI bg color sends theme update notifications when background changes #31652:
...
Running tests from test/functional/ui/output_spec.lua
...
WRN 2025-12-02T03:36:47.304 ui/c/T5831.28003.0 tui_handle_term_mode:223: TUI: terminal mode 2026 unavailable, state 0
WRN 2025-12-02T03:36:47.359 ui/c/T5832.28006.0 tui_handle_term_mode:223: TUI: terminal mode 2048 unavailable, state 0
WRN 2025-12-02T03:36:47.414 ui/c/T5833.28009.0 tui_handle_term_mode:223: TUI: terminal mode 2048 unavailable, state 0
Solution:
- Skip logging in test-mode.
- This can be reverted later, when these logs are changed to "INFO"
level, per this TODO comment:
```
// TODO(bfredl): This is really ILOG but we want it in all builds.
// add to show_verbose_terminfo() without being too racy ????
WLOG("TUI: terminal mode %d unavailable, state %d", mode, state);
```
