Fix crashes with AT-SPI2 screen readers (Orca) on Linux#3191
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danijel1124 wants to merge 2 commits into
Draft
Fix crashes with AT-SPI2 screen readers (Orca) on Linux#3191danijel1124 wants to merge 2 commits into
danijel1124 wants to merge 2 commits into
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QTableView with a screen reader active crashed in several ways due to bugs in Qt 6.4.x's QAccessibleTable implementation. This replaces the default accessibility backend for MyTableView with a custom one that: - Guards focusChild() against invalid (unselected) current index, preventing cellAt(-1,-1) calls that crash the AT-SPI2 bridge - Returns a dummy cell instead of nullptr from cellAt() and child(), working around a missing null-check in atspiadaptor.cpp - Uses QAccessible::Id (Qt-managed IDs) for the cell cache instead of raw pointers, preventing dangling-pointer crashes when the dialog is closed while a screen reader is active - Fixes child index mapping to account for header rows/columns, matching Qt's own accessibleTable2Index() formula - Implements all pure virtual methods of QAccessibleTableInterface Also adds ensureSelection() so the table always has a current index when shown, further reducing the chance of focus-related AT-SPI2 errors. Tested with Orca on Ubuntu 24.04 / Qt 6.4.2: server list opens, navigation works, reconnect works, dialog close works without crash. Assisted-By: Claude Sonnet 4.6 <noreply@anthropic.com>
bear101
reviewed
Mar 26, 2026
| void MyTableView::showEvent(QShowEvent* e) | ||
| { | ||
| QTableView::showEvent(e); | ||
| ensureSelection(); |
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| MyTableView::MyTableView(QWidget* parent/* = nullptr*/) : QTableView(parent) | ||
| { | ||
| QAccessible::installFactory(myTableViewFactory); |
Contributor
There was a problem hiding this comment.
This should probably have a:
#if defined(Q_OS_LINUX) && QT_VERSION == QT_VERSION_CHECK(6,4,0)
I'm not aware that other platforms have this issue or other Qt versions.
Contributor
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I'm changing this to Draft because the changes have unknown side effects on macOS and Windows as well as other versions of Qt. |
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Summary
QTableViewwith an active screen reader (Orca/AT-SPI2) crashed in several ways due to bugs in Qt 6.4.x'sQAccessibleTableimplementationMyTableViewwith a customMyTableViewAccessiblethat fixes all identified crash pathsWhat was fixed
focusChild()with no selection — guards against invalid current index, preventingcellAt(-1,-1)calls that crash the AT-SPI2 bridgechild()/cellAt()returning nullptr — returns a dummy cell instead, working around a missing null-check inatspiadaptor.cppQAccessible::Id(Qt-managed IDs) for the cell cache instead of raw pointersaccessibleTable2Index()formulaQAccessibleTableInterfaceimplementedensureSelection()— table always has a current index when shown, reducing AT-SPI2 focus errorsTest plan