2 files changed, 62 insertions, 1 deletions

diff --git a/src/widgets/widgets/qdialogbuttonbox.cpp b/src/widgets/widgets/qdialogbuttonbox.cpp
index 612b283825..7cd4d01d0a 100644
--- a/src/widgets/widgets/qdialogbuttonbox.cpp
+++ b/src/widgets/widgets/qdialogbuttonbox.cpp
@@ -1015,8 +1015,20 @@ void QDialogButtonBoxPrivate::ensureFirstAcceptIsDefault()
             break;
         }
     }
-    if (!hasDefault && firstAcceptButton)
+    if (!hasDefault && firstAcceptButton) {
         firstAcceptButton->setDefault(true);
+        // When the QDialogButtonBox is focused, and it doesn't have an
+        // explicit focus widget, it will transfer focus to its focus
+        // proxy, which is the first button in the layout. This behavior,
+        // combined with the behavior that QPushButtons in a QDialog will
+        // by default have their autoDefault set to true, results in the
+        // focus proxy/first button stealing the default button status
+        // immediately when the button box is focused, which is not what
+        // we want. Account for this by explicitly making the firstAcceptButton
+        // focused as well, unless an explicit focus widget has been set.
+        if (dialog && !dialog->focusWidget())
+            firstAcceptButton->setFocus();
+    }
 }
 
 void QDialogButtonBoxPrivate::disconnectAll()
diff --git a/tests/auto/widgets/widgets/qdialogbuttonbox/tst_qdialogbuttonbox.cpp b/tests/auto/widgets/widgets/qdialogbuttonbox/tst_qdialogbuttonbox.cpp
index 3f5ffa687b..9f405a8beb 100644
--- a/tests/auto/widgets/widgets/qdialogbuttonbox/tst_qdialogbuttonbox.cpp
+++ b/tests/auto/widgets/widgets/qdialogbuttonbox/tst_qdialogbuttonbox.cpp
@@ -81,6 +81,7 @@ private slots:
 
     void task191642_default();
     void testDeletedStandardButton();
+    void automaticDefaultButton();
 
 private:
     qint64 timeStamp;
@@ -909,5 +910,53 @@ void tst_QDialogButtonBox::testDeletedStandardButton()
     QVERIFY(!buttonC);
 }
 
+void tst_QDialogButtonBox::automaticDefaultButton()
+{
+    // Having a QDialogButtonBox inside a QDialog triggers Qt to
+    // enable autoDefault for QPushButtons inside the button box.
+    // Check that the logic for resolving a default button based
+    // on the Accept role is not overridden by the first button
+    // in the dialog (the focus proxy) taking focus, and hence
+    // stealing the default button state.
+
+    {
+        QDialog dialog;
+        QDialogButtonBox *bb = new QDialogButtonBox(&dialog);
+        // Force horizontal orientation, where we know the order between
+        // Reset and Accept roles are always the same for all layouts.
+        bb->setOrientation(Qt::Horizontal);
+        auto *okButton = bb->addButton(QDialogButtonBox::Ok);
+        auto *resetButton = bb->addButton(QDialogButtonBox::Reset);
+        // Double check our assumption about Reset being first
+        QCOMPARE(bb->layout()->itemAt(0)->widget(), resetButton);
+
+        dialog.show();
+        QVERIFY(QTest::qWaitForWindowActive(&dialog));
+
+        QVERIFY(okButton->isDefault());
+        QSignalSpy buttonClicked(okButton, &QPushButton::clicked);
+        QTest::keyPress(&dialog, Qt::Key_Enter);
+        QCOMPARE(buttonClicked.count(), 1);
+    }
+
+    // However, if an explicit button has been focused, we respect that.
+
+    {
+        QDialog dialog;
+        QDialogButtonBox *bb = new QDialogButtonBox(&dialog);
+        bb->setOrientation(Qt::Horizontal);
+        bb->addButton(QDialogButtonBox::Ok);
+        auto *resetButton = bb->addButton(QDialogButtonBox::Reset);
+        resetButton->setFocus();
+        dialog.show();
+        QVERIFY(QTest::qWaitForWindowActive(&dialog));
+
+        QVERIFY(resetButton->isDefault());
+        QSignalSpy buttonClicked(resetButton, &QPushButton::clicked);
+        QTest::keyPress(&dialog, Qt::Key_Enter);
+        QCOMPARE(buttonClicked.count(), 1);
+    }
+}
+
 QTEST_MAIN(tst_QDialogButtonBox)
 #include "tst_qdialogbuttonbox.moc"