McuSupport: Discard un-applied changes to Qul SDK package

The path to the Qul SDK entered in the settings path persisted in
the UI when re-opening the settings page, even if it was not
applied. Kits and the settings file are not affected unless
pressing apply so this did not affect functionality. Un-applied
changes are discarded by re-reading the path from the settings
file in the constructor for the settings page.

Task-number: QTCREATORBUG-28568
Change-Id: Id03be22fba429e4764493cd3bedf45faa6908637
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: Yasser Grimes <yasser.grimes@qt.io>
Reviewed-by: Alessandro Portale <alessandro.portale@qt.io>

src/plugins/mcusupport/mcuabstractpackage.h

@@ -47,6 +47,7 @@ public:
     virtual bool isValidStatus() const = 0;
 
     virtual bool writeToSettings() const = 0;
+    virtual void readFromSettings() = 0;
 
     virtual QWidget *widget() = 0;
     virtual const McuPackageVersionDetector *getVersionDetector() const = 0;

src/plugins/mcusupport/mcupackage.cpp

@@ -244,6 +244,11 @@ bool McuPackage::writeToSettings() const
     return settingsHandler->write(m_settingsKey, m_path, m_defaultPath);
 }
 
+void McuPackage::readFromSettings()
+{
+    setPath(settingsHandler->getPath(m_settingsKey, QSettings::UserScope, m_defaultPath));
+}
+
 QWidget *McuPackage::widget()
 {
     auto *widget = new QWidget;

src/plugins/mcusupport/mcupackage.h

@@ -66,6 +66,7 @@ public:
     QString statusText() const override;
 
     bool writeToSettings() const override;
+    void readFromSettings() override;
 
     QWidget *widget() override;
     const McuPackageVersionDetector *getVersionDetector() const override;

src/plugins/mcusupport/mcusupportoptionspage.cpp

@@ -90,6 +90,9 @@ McuSupportOptionsWidget::McuSupportOptionsWidget(McuSupportOptions &options,
         m_qtForMCUsSdkGroupBox = new QGroupBox(Tr::tr("Qt for MCUs SDK"));
         m_qtForMCUsSdkGroupBox->setFlat(true);
         auto *layout = new QVBoxLayout(m_qtForMCUsSdkGroupBox);
+        // Re-read the qtForMCUs package from settings to discard un-applied changes from previous sessions
+        m_options.qtForMCUsSdkPackage->readFromSettings();
+
         layout->addWidget(m_options.qtForMCUsSdkPackage->widget());
         mainLayout->addWidget(m_qtForMCUsSdkGroupBox);
     }

src/plugins/mcusupport/test/packagemock.h

@@ -29,6 +29,7 @@ public:
     MOCK_METHOD(QString, environmentVariableName, (), (const));
     MOCK_METHOD(bool, isAddToSystemPath, (), (const));
     MOCK_METHOD(bool, writeToSettings, (), (const));
+    MOCK_METHOD(void, readFromSettings, ());
     MOCK_METHOD(QStringList, versions, (), (const));
 
     MOCK_METHOD(QWidget *, widget, ());