Core: Avoid duplicating options page

Creating an IOptionPage registers it automatically. In case an
IOptionsProvider is used this duplicates the the option pages
and although duplicated still adds them to the respective
category again.
If one clicks on the respective tab this results in a crash.

Slipped in with cc88302309.

Change-Id: Ie881f532c3f0e397147d99ce368066cdce01a612
Reviewed-by: hjk <hjk@qt.io>

src/plugins/coreplugin/dialogs/ioptionspage.cpp

@@ -138,12 +138,13 @@ QIcon Core::IOptionsPage::categoryIcon() const
 static QList<Core::IOptionsPage *> g_optionsPages;
 
 /*!
-    Constructs an options page with the given \a parent.
+    Constructs an options page with the given \a parent and registers it
+    at the global options page pool if \a registerGlobally is true.
 */
-Core::IOptionsPage::IOptionsPage(QObject *parent)
+Core::IOptionsPage::IOptionsPage(QObject *parent, bool registerGlobally)
-    : QObject(parent),
+    : QObject(parent)
-      m_keywordsInitialized(false)
 {
+    if (registerGlobally)
         g_optionsPages.append(this);
 }
 

src/plugins/coreplugin/dialogs/ioptionspage.h

@@ -44,7 +44,7 @@ class CORE_EXPORT IOptionsPage : public QObject
     Q_OBJECT
 
 public:
-    IOptionsPage(QObject *parent = 0);
+    IOptionsPage(QObject *parent = nullptr, bool registerGlobally = true);
     virtual ~IOptionsPage();
 
     static const QList<IOptionsPage *> allOptionsPages();
@@ -73,7 +73,7 @@ protected:
     QString m_displayCategory;
     Utils::Icon m_categoryIcon;
 
-    mutable bool m_keywordsInitialized;
+    mutable bool m_keywordsInitialized = false;
     mutable QStringList m_keywords;
 };
 

src/plugins/designer/settingspage.cpp

@@ -37,6 +37,7 @@
 using namespace Designer::Internal;
 
 SettingsPage::SettingsPage(QDesignerOptionsPageInterface *designerPage) :
+    Core::IOptionsPage(nullptr, false),
     m_designerPage(designerPage)
 {
     setId(Core::Id::fromString(m_designerPage->name()));