Fix a deadlock on Windows when switching between longer diffs - #5815
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winPty.Close could block indefinitely, and it is called while holding the global PtyMutex and while the task's onDone sync.Once is executing, so blocking there wedges the task's entire cleanup chain: the next NewTask call blocks on <-notifyStopped while holding waitingMutex, every later task for that view queues up behind it, and onResize blocks on PtyMutex — a full UI freeze. (Reported by a user via go-deadlock's 30s watchdog; a regression from the ConPTY support introduced for v0.63.0.) ClosePseudoConsole is what blocks; before Windows 11 24H2 it can do so in two ways. It flushes the client's pending output into the out pipe, but a stopped task's scanner goroutine has already quit draining, so with a client that's still producing output the flush never completes; this can also wedge the background waiter's closeHpc, which runs with the pipes deliberately left open. And it waits for the console host to exit, but closing only delivers CTRL_CLOSE_EVENT to the attached client without terminating it, so a client that keeps running (git still computing an expensive diff, a pager waiting for input) keeps the host alive arbitrarily long. Run the teardown on a background goroutine so Close returns immediately no matter which of these strikes, and within it close our pipe ends before the pseudoconsole, without taking p.mu: breaking the pipes fails a pending flush fast, which also unblocks a waiter already stuck in one. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
stefanhaller
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The Windows PTY support that was newly introduced in v0.63.0 had a potential deadlock problem: when switching between longer diffs, lazygit could lock up. This should hopefully be fixed with this PR.
tmeijn
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This MR contains the following updates: | Package | Update | Change | |---|---|---| | [jesseduffield/lazygit](https://github.com/jesseduffield/lazygit) | patch | `v0.63.0` → `v0.63.1` | MR created with the help of [el-capitano/tools/renovate-bot](https://gitlab.com/el-capitano/tools/renovate-bot). **Proposed changes to behavior should be submitted there as MRs.** --- ### Release Notes <details> <summary>jesseduffield/lazygit (jesseduffield/lazygit)</summary> ### [`v0.63.1`](https://github.com/jesseduffield/lazygit/releases/tag/v0.63.1) [Compare Source](jesseduffield/lazygit@v0.63.0...v0.63.1) <!-- Release notes generated using configuration in .github/release.yml at v0.63.1 --> Fixes for a few regressions introduced in the v0.63.0 release. #### What's Changed ##### Fixes 🔧 - Improve index.lock retry mechanism by [@​stefanhaller](https://github.com/stefanhaller) in [#​5788](jesseduffield/lazygit#5788) - Fix userEvents panic by [@​stefanhaller](https://github.com/stefanhaller) in [#​5793](jesseduffield/lazygit#5793) - Fix a deadlock on Windows when switching between longer diffs by [@​stefanhaller](https://github.com/stefanhaller) in [#​5815](jesseduffield/lazygit#5815) ##### Maintenance ⚙️ - Allow releasing from a branch other than master by [@​stefanhaller](https://github.com/stefanhaller) in [#​5819](jesseduffield/lazygit#5819) **Full Changelog**: <jesseduffield/lazygit@v0.63.0...v0.63.1> </details> --- ### Configuration 📅 **Schedule**: (UTC) - Branch creation - At any time (no schedule defined) - Automerge - At any time (no schedule defined) 🚦 **Automerge**: Enabled. ♻ **Rebasing**: Whenever MR is behind base branch, or you tick the rebase/retry checkbox. 🔕 **Ignore**: Close this MR and you won't be reminded about this update again. --- - [ ] <!-- rebase-check -->If you want to rebase/retry this MR, check this box --- This MR has been generated by [Mend Renovate](https://github.com/renovatebot/renovate). <!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiI0My4yNjMuNiIsInVwZGF0ZWRJblZlciI6IjQzLjI2My42IiwidGFyZ2V0QnJhbmNoIjoibWFpbiIsImxhYmVscyI6WyJSZW5vdmF0ZSBCb3QiLCJhdXRvbWF0aW9uOmJvdC1hdXRob3JlZCIsImRlcGVuZGVuY3ktdHlwZTo6cGF0Y2giXX0=-->
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The Windows PTY support that was newly introduced in v0.63.0 had a potential deadlock problem: when switching between longer diffs, lazygit could lock up. This should hopefully be fixed with this PR.