PDF: Fix memory leak when the file has Optional Content links

core/document.cpp

@@ -2513,6 +2513,37 @@ void Document::closeDocument()
     // close the current document and save document info if a document is still opened
     if (d->m_generator && d->m_pagesVector.size() > 0) {
         d->saveDocumentInfo();
+
+        // free the content of the opaque backend actions (if any)
+        // this is a bit awkward since backends can store "random stuff" in the
+        // BackendOpaqueAction nativeId qvariant so we need to tell them to free it
+        // ideally we would just do that in the BackendOpaqueAction destructor
+        // but that's too late in the cleanup process, i.e. the generator has already closed its document
+        // and the document generator is nullptr
+        for (Page *p : qAsConst(d->m_pagesVector)) {
+            const QLinkedList<ObjectRect *> &oRects = p->objectRects();
+            for (ObjectRect *oRect : oRects) {
+                if (oRect->objectType() == ObjectRect::Action) {
+                    const Action *a = static_cast<const Action *>(oRect->object());
+                    const BackendOpaqueAction *backendAction = dynamic_cast<const BackendOpaqueAction *>(a);
+                    if (backendAction) {
+                        d->m_generator->freeOpaqueActionContents(*backendAction);
+                    }
+                }
+            }
+
+            const QLinkedList<FormField *> forms = p->formFields();
+            for (const FormField *form : forms) {
+                const QList<Action *> additionalActions = form->additionalActions();
+                for (const Action *a : additionalActions) {
+                    const BackendOpaqueAction *backendAction = dynamic_cast<const BackendOpaqueAction *>(a);
+                    if (backendAction) {
+                        d->m_generator->freeOpaqueActionContents(*backendAction);
+                    }
+                }
+            }
+        }
+
         d->m_generator->closeDocument();
     }
 

core/form.cpp

@@ -115,6 +115,13 @@ void FormField::setAdditionalAction(Annotation::AdditionalActionType type, Actio
     d->m_additionalAnnotActions[type] = action;
 }
 
+QList<Action *> FormField::additionalActions() const
+{
+    Q_D(const FormField);
+    // yes, calling values() is not great but it's a list of ~10 elements, we can live with that
+    return d->m_additionalAnnotActions.values() + d->m_additionalActions.values(); // clazy:exclude=container-anti-pattern
+}
+
 class Okular::FormFieldButtonPrivate : public Okular::FormFieldPrivate
 {
 public:

core/form.h

@@ -157,6 +157,12 @@ public:
      */
     Action *additionalAction(Annotation::AdditionalActionType type) const;
 
+    /* Returns all the additional actions for this form
+     *
+     * @since 22.04
+     */
+    QList<Action *> additionalActions() const;
+
 protected:
     /// @cond PRIVATE
     explicit FormField(FormFieldPrivate &dd);

core/generator.cpp

@@ -386,6 +386,10 @@ void Generator::opaqueAction(const BackendOpaqueAction * /*action*/)
 {
 }
 
+void Generator::freeOpaqueActionContents(const BackendOpaqueAction & /*action*/)
+{
+}
+
 QVariant Generator::metaData(const QString &key, const QVariant &option) const
 {
     Q_D(const Generator);

core/generator.h

@@ -451,6 +451,13 @@ public:
      */
     virtual void opaqueAction(const BackendOpaqueAction *action);
 
+    /**
+     * Frees the contents of the opaque action (if any);
+     *
+     * @since 22.04
+     */
+    virtual void freeOpaqueActionContents(const BackendOpaqueAction &action);
+
 Q_SIGNALS:
     /**
      * This signal should be emitted whenever an error occurred in the generator.

core/page.cpp

@@ -582,6 +582,11 @@ void Page::setObjectRects(const QLinkedList<ObjectRect *> &rects)
     m_rects << rects;
 }
 
+const QLinkedList<ObjectRect *> &Page::objectRects() const
+{
+    return m_rects;
+}
+
 void PagePrivate::setHighlight(int s_id, RegularAreaRect *rect, const QColor &color)
 {
     HighlightAreaRect *hr = new HighlightAreaRect(rect);

core/page.h

@@ -283,6 +283,13 @@ public:
      */
     void setObjectRects(const QLinkedList<ObjectRect *> &rects);
 
+    /**
+     * Gets the list of object rects of the page.
+     *
+     * @since 22.04
+     */
+    const QLinkedList<ObjectRect *> &objectRects() const;
+
     /**
      * Sets the list of source reference objects @p rects.
      */

generators/poppler/generator_pdf.cpp

@@ -1008,6 +1008,11 @@ void PDFGenerator::opaqueAction(const Okular::BackendOpaqueAction *action)
     pdfdoc->optionalContentModel()->applyLink(const_cast<Poppler::LinkOCGState *>(popplerLink));
 }
 
+void PDFGenerator::freeOpaqueActionContents(const Okular::BackendOpaqueAction &action)
+{
+    delete action.nativeId().value<const Poppler::LinkOCGState *>();
+}
+
 bool PDFGenerator::isAllowed(Okular::Permission permission) const
 {
     bool b = true;

generators/poppler/generator_pdf.h

@@ -71,6 +71,7 @@ public:
     }
     QAbstractItemModel *layersModel() const override;
     void opaqueAction(const Okular::BackendOpaqueAction *action) override;
+    void freeOpaqueActionContents(const Okular::BackendOpaqueAction &action) override;
 
     // [INHERITED] document information
     bool isAllowed(Okular::Permission permission) const override;