fix(gestures): separate unregister from delete to avoid use-after-free

[deepin-wm]

unregisterSwipeGesture/unregisterHoldGesture previously called deleteLater() on the gesture object. This is dangerous because:

1. The QObject::destroyed signal handler also calls unregister, creating a circular dependency.
2. Callers may still reference the gesture after unregister.

Add removeSwipeGesture/removeHoldGesture that call unregister then deleteLater, and update InputDevice callers to use the new methods.

Extracted from #1046. Ref: WM-29

Summary by Sourcery

Separate gesture unregistration from object deletion to avoid use-after-free issues in gesture handling.

Bug Fixes:

• Fix potential use-after-free by ensuring swipe and hold gestures are only deleted after being cleanly unregistered from the recognizer.

Enhancements:

• Introduce removeSwipeGesture and removeHoldGesture helpers that unregister and then schedule deletion of gesture objects, updating InputDevice to use these safer APIs.

[deepin-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: deepin-wm

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[sourcery-ai]

Reviewer's guide (collapsed on small PRs)

Reviewer's Guide

Introduces separate removal methods for swipe and hold gestures that decouple unregistration from object deletion to avoid use-after-free and circular destruction issues, and updates InputDevice to use the new APIs.

Sequence diagram for updated gesture removal flow

sequenceDiagram
    participant InputDevice
    participant GestureRecognizer
    participant SwipeGesture

    InputDevice->>GestureRecognizer: unregisterTouchpadSwipe(gesture)
    GestureRecognizer->>GestureRecognizer: removeSwipeGesture(gesture)
    GestureRecognizer->>GestureRecognizer: unregisterSwipeGesture(gesture)
    GestureRecognizer->>SwipeGesture: deleteLater()

    InputDevice->>GestureRecognizer: unregisterTouchpadHold(gesture)
    GestureRecognizer->>GestureRecognizer: removeHoldGesture(gesture)
    GestureRecognizer->>GestureRecognizer: unregisterHoldGesture(gesture)
    GestureRecognizer->>HoldGesture: deleteLater()

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File-Level Changes

Change	Details	Files
Split gesture unregistration from object deletion to prevent use-after-free and circular destruction callbacks.	Stop calling deleteLater() inside unregisterSwipeGesture and unregisterHoldGesture. Introduce removeSwipeGesture and removeHoldGesture that first unregister the gesture and then schedule it for deletion. Ensure gesture cancellation continues to be emitted on unregistration before deletion.	src/input/gestures.cpp src/input/gestures.h
Update InputDevice gesture cleanup to use the new removal methods.	Change unregisterTouchpadSwipe to call removeSwipeGesture instead of unregisterSwipeGesture. Change unregisterTouchpadHold to call removeHoldGesture instead of unregisterHoldGesture.	src/input/inputdevice.cpp

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[deepin-bot]

TAG Bot

New tag: 0.8.14
DISTRIBUTION: unstable
Suggest: synchronizing this PR through rebase #1123

[deepin-bot]

TAG Bot

New tag: 0.8.15
DISTRIBUTION: unstable
Suggest: synchronizing this PR through rebase #1163