jesseduffield.lazygit/pkg/commands
Stefan Haller 6048fee49d Kill the pty child's process tree on Windows to avoid orphans (#5879)
Stopping a pty task on Windows relies on ClosePseudoConsole, which
delivers CTRL_CLOSE_EVENT to the console's attached clients. But only
to those attached at that moment: when the user flicks quickly through
commits, a task is often stopped within the first few milliseconds of
its life, before the child has attached to the pseudoconsole. Such a
child misses the event and survives, running the entire diff to
completion in the background (spawning one external differ per changed
file) and keeping its conhost.exe alive; rapid navigation accumulates
these git/difft/conhost trees, and they outlive lazygit. Grandchildren
are affected too: git for Windows runs commands through a two-level
git.exe wrapper, so a single task has several attach windows, and a
grandchild spawned while the console is going down is orphaned even
when its parent got the event and exited.

Fix this by putting the child into a job object before it runs its
first instruction (created suspended, assigned, then resumed), so that
every descendant is in the job from the start; the teardown in Close
terminates the job right after initiating the pseudoconsole close.
There is no point in a grace period between the two: the close event
is not a graceful signal -- git and the common diff tools leave it to
the default handler, which calls ExitProcess at an arbitrary point --
so clients that received it are already dying, and the kill exists for
those that missed it. Killing at an arbitrary point cannot leak a
stale index.lock, because pty-rendered commands no longer take that
lock (see withPtyGitConfig in pkg/gui/pty.go).

The pseudoconsole close runs on its own goroutine because the kill
must not wait for it: on builds where ClosePseudoConsole blocks until
the console host exits (pre-24H2), the host keeps running as long as a
surviving client does, and that client only goes away through the job
kill; sequencing the kill after a blocking close would deadlock in
exactly the case the kill exists for.

KILL_ON_JOB_CLOSE doubles as a safety net: if lazygit exits without
running the teardown, the OS closes the job handle and reaps the tree.

In a harness that mimicked the stop path with randomized 0-120ms stop
delays, 3 of 30 process trees survived as orphans before this change;
none survive with it.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
2026-08-04 07:03:27 +02:00
..
direnv Offer direnv .envrc approval from inside lazygit 2026-06-04 09:05:01 +02:00
git_commands Carry aggregate check state with GitHub pull requests 2026-07-31 09:01:44 +02:00
git_config Pin the cached git config's commands to the repo directory 2026-07-20 17:07:39 +02:00
hosting_service Optimize regex compilations 2026-05-10 15:28:14 +02:00
models Carry aggregate check state with GitHub pull requests 2026-07-31 09:01:44 +02:00
oscommands Kill the pty child's process tree on Windows to avoid orphans (#5879) 2026-08-04 07:03:27 +02:00
patch Guard the patch builder against concurrent access 2026-07-17 12:35:54 +02:00
testdata Support opening lazygit in a submodule 2019-05-12 17:59:49 +10:00
git.go Rework the custom pager config (rename to diff renderer) 2026-07-31 08:42:51 +02:00
git_cmd_obj_builder.go Pin git commands to the repo they were created for 2026-07-20 17:07:39 +02:00
git_cmd_obj_builder_test.go Pin git commands to the repo they were created for 2026-07-20 17:07:39 +02:00
git_cmd_obj_runner.go Back off exponentially between lock-error retries 2026-07-15 10:08:44 +02:00
git_cmd_obj_runner_test.go Back off exponentially between lock-error retries 2026-07-15 10:08:44 +02:00