path: root/src/widgets/kernel/qlayout_p.h
diff options
authorThomas Fischer <>2014-08-24 14:01:26 +0200
committerMarc Mutz <>2014-09-05 00:05:45 +0200
commit983dde1f2f3db76ab26e949d8c2f4f8b968b36be (patch)
treec092b9aa473e4ca41201ab1969f9139ff9db8585 /src/widgets/kernel/qlayout_p.h
parent8206a263ab9bca7fef191d299c05294a00ec1c8f (diff)
Avoid adding widget to its own layout
Widgets and layouts added or inserted to a layout are checked for: - Not being NULL - Not being the parent widget of a layout or the layout itself, respectively Without this commit, adding a widget to its own layout would result in a CPU-hogging infinite loop. Now, a warning is written to stderr and the add or insert function call is ignored. The checks are implemented as public functions of QLayoutPrivate and thus accessible in QLayout's descendants to be used in various "addWidget", "insertWidget", etc functions. Unlike 'classical' layouts like QGridLayout, QFormLayout does indeed accept widgets that are NULL. To not break this behavior, any call for the check functions first tests if the widget or layout, respectively, to test is NULL or not and calls the check only in the latter case. Automated tests for QBoxLayout, QGridLayout, and QFormLayout were added. For an unpatched Qt 5.3, each of those automated tests will freeze as explained in QTBUG-40609. For a fixed version, warning messages about invalid parameters to addWidget/addLayout/... calls will be read by QTest::ignoreMessage, resulting in a passed test. Change-Id: I1522d5727e643da3f7c025755975aca9f482676d Task-number: QTBUG-40609 Reviewed-by: Marc Mutz <>
Diffstat (limited to 'src/widgets/kernel/qlayout_p.h')
1 files changed, 2 insertions, 0 deletions
diff --git a/src/widgets/kernel/qlayout_p.h b/src/widgets/kernel/qlayout_p.h
index 2100d86aba..71e0f9bcd3 100644
--- a/src/widgets/kernel/qlayout_p.h
+++ b/src/widgets/kernel/qlayout_p.h
@@ -76,6 +76,8 @@ public:
void getMargin(int *result, int userMargin, QStyle::PixelMetric pm) const;
void doResize(const QSize &);
void reparentChildWidgets(QWidget *mw);
+ bool checkWidget(QWidget *widget) const;
+ bool checkLayout(QLayout *otherLayout) const;
static QWidgetItem *createWidgetItem(const QLayout *layout, QWidget *widget);
static QSpacerItem *createSpacerItem(const QLayout *layout, int w, int h, QSizePolicy::Policy hPolicy = QSizePolicy::Minimum, QSizePolicy::Policy vPolicy = QSizePolicy::Minimum);