Keep a busy system clipboard from crashing the desktop app - #307
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No actionable comments were generated in the recent review. 🎉 ℹ️ Recent review info⚙️ Run configurationConfiguration used: defaults Review profile: CHILL Plan: Pro Plus Run ID: 📒 Files selected for processing (1)
Included review availability: 6 reviews are currently available. Your included PR review attempts over the past 7 days set your current allowance at 8 reviews per hour. 📝 WalkthroughWalkthroughAdds a retrying ChangesSafe clipboard handling
Estimated code review effort: 3 (Moderate) | ~20 minutes Merge Risk: ⚪ Minimal · up to This change adds guarded clipboard handling for desktop copy operations and reports passing checks; no actionable merge-blocking risk remains. Sequence Diagram(s)sequenceDiagram
participant Main
participant LocalClipboard
participant DesktopScene
participant SafeClipboard
participant NativeClipboard
Main->>SafeClipboard: rememberSafeClipboard()
Main->>LocalClipboard: provide safe clipboard
DesktopScene->>LocalClipboard: obtain clipboard
DesktopScene->>SafeClipboard: write clipboard entry
SafeClipboard->>NativeClipboard: attempt write
NativeClipboard-->>SafeClipboard: busy failure or success
SafeClipboard->>NativeClipboard: retry after delay
SafeClipboard-->>DesktopScene: write result
🚥 Pre-merge checks | ✅ 4 | ❌ 1❌ Failed checks (1 warning)
✅ Passed checks (4 passed)
✨ Finishing Touches 💡 1📝 Generate docstrings 💡
🧪 Generate unit tests (beta)
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Inline comments:
In
`@compose/src/jvmTest/kotlin/warlockfe/warlock3/compose/util/SafeClipboardTest.kt`:
- Line 136: Make the failures collection in SafeClipboardTest thread-safe for
writes from both exception handlers and reads by the test thread, preserving the
existing failure-recording and assertion behavior.
In `@desktopApp/src/main/kotlin/warlockfe/warlock3/app/MemoryUsageDialog.kt`:
- Around line 155-157: Update the copy flow in MemoryUsageDialog so
SafeClipboard.setClipEntry exposes whether the write succeeded, and set the
“Report copied” status only after a successful write; preserve failure without
reporting success. Also coordinate this coroutine with busy or use separate copy
status so delayed completion cannot overwrite refresh or heap-dump operation
status.
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ℹ️ Review info
⚙️ Run configuration
Configuration used: defaults
Review profile: CHILL
Plan: Pro Plus
Run ID: 16345ba2-be25-468a-a957-d97fe1a28bc5
📒 Files selected for processing (7)
compose/src/jvmMain/kotlin/warlockfe/warlock3/compose/desktop/shim/WarlockDialog.ktcompose/src/jvmMain/kotlin/warlockfe/warlock3/compose/desktop/ui/game/DesktopGameView.ktcompose/src/jvmMain/kotlin/warlockfe/warlock3/compose/desktop/ui/settings/DesktopSettingsDialog.ktcompose/src/jvmMain/kotlin/warlockfe/warlock3/compose/util/SafeClipboard.ktcompose/src/jvmTest/kotlin/warlockfe/warlock3/compose/util/SafeClipboardTest.ktdesktopApp/src/main/kotlin/warlockfe/warlock3/app/Main.ktdesktopApp/src/main/kotlin/warlockfe/warlock3/app/MemoryUsageDialog.kt
Included review availability: 6 reviews are currently available. Your included PR review attempts over the past 7 days set your current allowance at 8 reviews per hour.
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Review feedback on #307. SafeClipboard swallowing a failed write left two callers believing it had worked. The memory dialog said "Report copied to the clipboard" either way, and {cut} deletes what it copies once copyToClipboard says the text is safe - so a clipboard that stayed busy through the retries would have taken the entry text with nothing to paste back. The write threw before this branch, which at least left the text alone. trySetClipEntry is the retrying write with its outcome; setClipEntry is the same write with the outcome dropped, which is all Compose's own copy handlers can use anyway. The class moves to commonMain so GameViewModel can ask for the outcome; mobile still gets the platform clipboard, whose throw the other branch preserves. Also make the scene test's failure list a CopyOnWriteArrayList - the compose thread's two handlers write it while the test thread reads it - and correct the class doc: kotlinx's final-resort path calls the uncaught handler rather than unwinding, so what this cost was a fatal crash report and a copy that silently did nothing, not necessarily the process. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_017RkdXBG9uKnWyVaLW3Qz7k
DESKTOP-2G, on 3.1.0: copying out of a game window took the client down with IllegalStateException: cannot open system clipboard. Windows lets one process hold the clipboard open at a time and AWT does not wait its turn, so setContents throws whenever something else has it - another app's copy, a clipboard manager's poll, a remote desktop session syncing it. Compose's SelectionContainer runs its copy in a launched coroutine with nothing to catch that, and every text field does the same, so the throw went straight to the uncaught handler. The only way into Compose's own copy is the clipboard it reads, so SafeClipboard wraps the platform one: a retry a moment later usually gets the lock, and a copy that never lands is logged and dropped rather than thrown. CancellationException is rethrown ahead of it - on the JVM it is an IllegalStateException, and swallowing it would strand a cancelled coroutine - and the deprecated nativeClipboard is delegated, which Compose's desktop context menu still reads. Provided per Compose scene, because a dialog or a detached window is a new scene whose own locals override whatever the parent composition provided: the main window, the docked window content (the only part of a detached window that is ours), the WarlockDialog shim and the settings dialog. The memory dialog's "copy report" reached AWT directly and could throw off the event thread, so it goes through the window's clipboard now too. Android and iOS are left alone; this is an AWT failure mode. The last test drives the production path rather than the wrapper - a SelectionContainer in a real scene, selectAll, a copy key event, against a clipboard that is busy twice - and fails if the provider is taken away. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_017RkdXBG9uKnWyVaLW3Qz7k
Review feedback on #307. SafeClipboard swallowing a failed write left two callers believing it had worked. The memory dialog said "Report copied to the clipboard" either way, and {cut} deletes what it copies once copyToClipboard says the text is safe - so a clipboard that stayed busy through the retries would have taken the entry text with nothing to paste back. The write threw before this branch, which at least left the text alone. trySetClipEntry is the retrying write with its outcome; setClipEntry is the same write with the outcome dropped, which is all Compose's own copy handlers can use anyway. The class moves to commonMain so GameViewModel can ask for the outcome; mobile still gets the platform clipboard, whose throw the other branch preserves. Also make the scene test's failure list a CopyOnWriteArrayList - the compose thread's two handlers write it while the test thread reads it - and correct the class doc: kotlinx's final-resort path calls the uncaught handler rather than unwinding, so what this cost was a fatal crash report and a copy that silently did nothing, not necessarily the process. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_017RkdXBG9uKnWyVaLW3Qz7k
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Fixes DESKTOP-2G (
IllegalStateException: cannot open system clipboard, fatal, 3.1.0).What was happening
Windows lets one process hold the clipboard open at a time and AWT does not wait its turn:
setContentsthrows whenever something else has it — another app's copy, a clipboard manager's poll, a remote desktop session syncing it. Compose'sSelectionContainerruns its copy inlaunch(UNDISPATCHED) { clipboard.setClipEntry(...) }with nothing to catch that, and every text field does the same, so the throw went straight to the uncaught handler and took the client down.The fix
The only way into Compose's own copy is the
LocalClipboardit reads, soSafeClipboarddecorates the platform one: retry a busy clipboard (4 attempts, 50 ms apart — whoever holds the lock is normally mid-operation), then log and drop.CancellationExceptionis rethrown ahead of the retry, since on the JVM it is anIllegalStateExceptionand swallowing it would strand a cancelled coroutine, and the deprecatednativeClipboardis delegated because Compose's desktop context menu still reads it.It is provided per Compose scene, because a dialog or a detached window is a new scene whose own
ProvideCommonCompositionLocalsoverrides whatever the parent composition provided:Main.kt— the main window: game windows, entry field, dashboard, in-window popupsDesktopGameView.windowContent— detached game windows, whose scene the docking library opens from the application scope; that lambda is the only part of it that is oursWarlockDialog— every dialog built on the shim (import results, about, memory, character select, alerts)DesktopSettingsDialog— its ownDialogWindow, full of text fieldsMemoryUsageDialog's "copy report" reachedToolkit.getDefaultToolkit().systemClipboarddirectly and could throw off the event thread the same way, so it goes through the window's clipboard now too.Android and iOS are left alone: this is an AWT failure mode, and their clipboards are different implementations.
UpdateDialogis left alone as well — no selectable text, no clipboard use.Tests
SafeClipboardTestcovers retry-then-succeed in both directions, giving up, cancellation not being mistaken for a busy clipboard, non-lock failures not being waited out, idempotent wrapping, and the delegated native clipboard.The last test drives the production path rather than the wrapper: a
SelectionContainerin anImageComposeScene,selectAll(), a copy key event, against a clipboard that is busy twice. The text lands and nothing reaches the scene's exception handler — and takingProvideSafeClipboardback out makes it fail, so it pins the fix rather than the fake../gradlew check -PiosSkip=true -PlintSkip=truepasses.🤖 Generated with Claude Code
https://claude.ai/code/session_017RkdXBG9uKnWyVaLW3Qz7k
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