Fix broken page MiniBar

The `MiniBar` normally used to display page numbers and to provide
navigation buttons regressed since 01557c16c4 to only show an empty
non-functional button called "Page Number", along with multiple
warnings:
`QObject::connect(MiniBar, QAction): invalid nullptr parameter`

This is caused by moving `setupViewerActions()` to a place where
`m_miniBar` is not initialized yet, even though it has a runtime
`connect`-dependency on it.

By moving `setupViewerActions()` back, the `MiniBar` starts working
again. Now the `m_addBookmark` action, which is created in that
function, is not available anymore to be passed to the constructor of
`BookmarkList`. To avoid moving the setup of the latter away from the
rest of the sidebar code, only assigning the action to the bookmark
button contained in the `BookmarkList` is deferred to
`setupViewerActions()`.

As requested, any accidental future `nullptr`-access will be handled by
crashing, even in Release builds, by omitting any checks.

BUG: 450347

Test Plan:

Page numbers show up again in toolbar, no more `connect` warnings.

part/bookmarklist.cpp

@@ -117,7 +117,7 @@ public:
     }
 };
 
-BookmarkList::BookmarkList(Okular::Document *document, QAction *addBookmarkAction, QWidget *parent)
+BookmarkList::BookmarkList(Okular::Document *document, QWidget *parent)
     : QWidget(parent)
     , m_document(document)
     , m_currentDocumentItem(nullptr)
@@ -161,11 +161,10 @@ BookmarkList::BookmarkList(Okular::Document *document, QAction *addBookmarkActio
 
     rebuildTree(m_showForAllDocumentsCheckbox->isChecked());
 
-    QToolButton *showAllToolButton = new QToolButton(this);
-    showAllToolButton->setDefaultAction(addBookmarkAction);
-    showAllToolButton->setAutoRaise(true);
-    showAllToolButton->setToolButtonStyle(Qt::ToolButtonTextBesideIcon);
-    mainlay->addWidget(showAllToolButton);
+    m_showAllToolButton = new QToolButton(this);
+    m_showAllToolButton->setAutoRaise(true);
+    m_showAllToolButton->setToolButtonStyle(Qt::ToolButtonTextBesideIcon);
+    mainlay->addWidget(m_showAllToolButton);
 }
 
 BookmarkList::~BookmarkList()
@@ -198,6 +197,11 @@ void BookmarkList::notifySetup(const QVector<Okular::Page *> &pages, int setupFl
     }
 }
 
+void BookmarkList::setAddBookmarkAction(QAction *addBookmarkAction)
+{
+    m_showAllToolButton->setDefaultAction(addBookmarkAction);
+}
+
 void BookmarkList::slotShowAllBookmarks(bool showAll)
 {
     rebuildTree(showAll);

part/bookmarklist.h

@@ -13,6 +13,7 @@
 
 class QAction;
 class QCheckBox;
+class QToolButton;
 class QTreeWidget;
 class QTreeWidgetItem;
 class KTreeWidgetSearchLine;
@@ -30,12 +31,14 @@ class BookmarkList : public QWidget, public Okular::DocumentObserver
     Q_OBJECT
 
 public:
-    explicit BookmarkList(Okular::Document *document, QAction *addBookmarkAction, QWidget *parent = nullptr);
+    explicit BookmarkList(Okular::Document *document, QWidget *parent = nullptr);
     ~BookmarkList() override;
 
     // inherited from DocumentObserver
     void notifySetup(const QVector<Okular::Page *> &pages, int setupFlags) override;
 
+    void setAddBookmarkAction(QAction *addBookmarkAction);
+
 private Q_SLOTS:
     void slotShowAllBookmarks(bool);
     void slotExecuted(QTreeWidgetItem *item);
@@ -56,6 +59,7 @@ private:
     KTreeWidgetSearchLine *m_searchLine;
     QCheckBox *m_showForAllDocumentsCheckbox;
     QTreeWidgetItem *m_currentDocumentItem;
+    QToolButton *m_showAllToolButton;
 };
 
 #endif

part/part.cpp

@@ -377,8 +377,6 @@ Part::Part(QWidget *parentWidget, QObject *parent, const QVariantList &args)
     //      sLabel->setBuddy( m_searchWidget );
     //      m_searchToolBar->setStretchableWidget( m_searchWidget );
 
-    setupViewerActions();
-
     // [left toolbox optional item: Table of Contents] | []
     m_toc = new TOC(nullptr, m_document);
     connect(m_toc.data(), &TOC::hasTOC, this, &Part::enableTOC);
@@ -406,7 +404,7 @@ Part::Part(QWidget *parentWidget, QObject *parent, const QVariantList &args)
     m_sidebar->addItem(m_reviewsWidget, QIcon::fromTheme(QStringLiteral("draw-freehand")), i18n("Annotations"));
 
     // [left toolbox: Bookmarks] | []
-    m_bookmarkList = new BookmarkList(m_document, m_addBookmark, nullptr);
+    m_bookmarkList = new BookmarkList(m_document, nullptr);
     m_sidebar->addItem(m_bookmarkList, QIcon::fromTheme(QStringLiteral("bookmarks")), i18n("Bookmarks"));
 
     // [left toolbox optional item: Signature Panel] | []
@@ -538,6 +536,8 @@ Part::Part(QWidget *parentWidget, QObject *parent, const QVariantList &args)
 
     connect(m_document->bookmarkManager(), &BookmarkManager::saved, this, &Part::slotRebuildBookmarkMenu);
 
+    setupViewerActions();
+
     if (m_embedMode != ViewerWidgetMode) {
         setupActions();
     } else {
@@ -711,6 +711,7 @@ void Part::setupViewerActions()
     m_addBookmark = KStandardAction::addBookmark(this, SLOT(slotAddBookmark()), ac);
     m_addBookmarkText = m_addBookmark->text();
     m_addBookmarkIcon = m_addBookmark->icon();
+    m_bookmarkList->setAddBookmarkAction(m_addBookmark);
 
     m_renameBookmark = ac->addAction(QStringLiteral("rename_bookmark"));
     m_renameBookmark->setText(i18n("Rename Bookmark"));