Fix crash when adding an external editor

On some platforms, the app chooser dialog causes a crash after selecting
an application. The application information returned by the dialog may
also trigger crashes when accessed. See
https://gitlab.gnome.org/GNOME/glib/-/issues/1104 and
https://gitlab.gnome.org/GNOME/glibmm/-/issues/94. This commit overrides
gtkmm's app chooser dialog to work around these bugs.

rtgui/CMakeLists.txt

@@ -135,6 +135,7 @@ set(NONCLISOURCEFILES
     retinex.cc
     rgbcurves.cc
     rotate.cc
+    rtappchooserdialog.cc
     rtimage.cc
     rtscalable.cc
     rtsurface.cc

rtgui/editorpanel.cc

@@ -39,6 +39,7 @@
 #include "procparamchangers.h"
 #include "placesbrowser.h"
 #include "pathutils.h"
+#include "rtappchooserdialog.h"
 #include "thumbnail.h"
 #include "toolpanelcoord.h"
 
@@ -2014,7 +2015,7 @@ void EditorPanel::sendToExternalPressed()
 {
     if (options.externalEditorIndex == -1) {
         // "Other" external editor. Show app chooser dialog to let user pick.
-        Gtk::AppChooserDialog *dialog = getAppChooserDialog();
+        RTAppChooserDialog *dialog = getAppChooserDialog();
         dialog->show();
     } else {
         struct ExternalEditor editor = options.externalEditors.at(options.externalEditorIndex);
@@ -2195,10 +2196,10 @@ bool EditorPanel::idle_sentToGimp (ProgressConnector<int> *pc, rtengine::IImagef
     return false;
 }
 
-Gtk::AppChooserDialog *EditorPanel::getAppChooserDialog()
+RTAppChooserDialog *EditorPanel::getAppChooserDialog()
 {
     if (!app_chooser_dialog.get()) {
-        app_chooser_dialog.reset(new Gtk::AppChooserDialog("image/tiff"));
+        app_chooser_dialog.reset(new RTAppChooserDialog("image/tiff"));
         app_chooser_dialog->signal_response().connect(
             sigc::mem_fun(*this, &EditorPanel::onAppChooserDialogResponse)
         );

rtgui/editorpanel.h

@@ -46,6 +46,7 @@ class FilePanel;
 class MyProgressBar;
 class Navigator;
 class PopUpButton;
+class RTAppChooserDialog;
 class Thumbnail;
 class ToolPanelCoordinator;
 
@@ -212,7 +213,7 @@ private:
     bool                idle_sendToGimp ( ProgressConnector<rtengine::IImagefloat*> *pc, Glib::ustring fname);
     bool                idle_sentToGimp (ProgressConnector<int> *pc, rtengine::IImagefloat* img, Glib::ustring filename);
     void                histogramProfile_toggled ();
-    Gtk::AppChooserDialog *getAppChooserDialog();
+    RTAppChooserDialog *getAppChooserDialog();
     void onAppChooserDialogResponse(int resposneId);
     void updateExternalEditorSelection();
 
@@ -249,7 +250,7 @@ private:
     Gtk::Button* navNext;
     Gtk::Button* navPrev;
     Glib::RefPtr<Gio::AppInfo> external_editor_info;
-    std::unique_ptr<Gtk::AppChooserDialog> app_chooser_dialog;
+    std::unique_ptr<RTAppChooserDialog> app_chooser_dialog;
     ExternalEditorChangedSignal *externalEditorChangedSignal;
     sigc::connection externalEditorChangedSignalConnection;
 

rtgui/externaleditorpreferences.cc

@@ -164,7 +164,7 @@ Gtk::TreeViewColumn *ExternalEditorPreferences::makeCommandColumn()
 }
 
 void ExternalEditorPreferences::onAppChooserDialogResponse(
-    int response_id, Gtk::AppChooserDialog *dialog)
+    int response_id, RTAppChooserDialog *dialog)
 {
     switch (response_id) {
         case Gtk::RESPONSE_OK:
@@ -190,7 +190,7 @@ void ExternalEditorPreferences::openAppChooserDialog()
         return;
     }
 
-    app_chooser_dialog.reset(new Gtk::AppChooserDialog("image/tiff"));
+    app_chooser_dialog.reset(new RTAppChooserDialog("image/tiff"));
     app_chooser_dialog->signal_response().connect(sigc::bind(
                 sigc::mem_fun(*this, &ExternalEditorPreferences::onAppChooserDialogResponse),
                 app_chooser_dialog.get()

rtgui/externaleditorpreferences.h

@@ -18,7 +18,6 @@
  */
 #pragma once
 
-#include <gtkmm/appchooserdialog.h>
 #include <gtkmm/button.h>
 #include <gtkmm/box.h>
 #include <gtkmm/liststore.h>
@@ -26,6 +25,8 @@
 #include <gtkmm/treemodelcolumn.h>
 #include <gtkmm/treeview.h>
 
+#include "rtappchooserdialog.h"
+
 
 /**
  * Widget for editing the external editors options.
@@ -98,7 +99,7 @@ private:
     Gtk::Button *button_app_chooser;
     Gtk::Button *button_add;
     Gtk::Button *button_remove;
-    std::unique_ptr<Gtk::AppChooserDialog> app_chooser_dialog;
+    std::unique_ptr<RTAppChooserDialog> app_chooser_dialog;
 
     /**
      * Inserts a new editor entry after the current selection, or at the end if
@@ -117,7 +118,7 @@ private:
      * Called when the user is done interacting with the app chooser dialog.
      * Closes the dialog and updates the selected entry if an app was chosen.
      */
-    void onAppChooserDialogResponse(int responseId, Gtk::AppChooserDialog *dialog);
+    void onAppChooserDialogResponse(int responseId, RTAppChooserDialog *dialog);
     /**
      * Shows the app chooser dialog.
      */

rtgui/rtappchooserdialog.cc

@@ -0,0 +1,77 @@
+/*
+ *  This file is part of RawTherapee.
+ *
+ *  Copyright (c) 2021 Lawrence Lee <billee@ucdavis.edu>
+ *
+ *  RawTherapee is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  RawTherapee is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with RawTherapee.  If not, see <https://www.gnu.org/licenses/>.
+ */
+#include "rtappchooserdialog.h"
+
+#if !(defined WIN32 || defined __APPLE__)
+#define GTKMM_APPCHOOSERDIALOG
+#endif
+
+RTAppChooserDialog::~RTAppChooserDialog() {}
+
+#ifdef GTKMM_APPCHOOSERDIALOG // Use Gtk::AppChooserDialog directly.
+
+RTAppChooserDialog::RTAppChooserDialog(const Glib::ustring &content_type) :
+    Gtk::AppChooserDialog(content_type)
+{
+}
+
+Glib::RefPtr<Gio::AppInfo> RTAppChooserDialog::get_app_info()
+{
+    return Gtk::AppChooserDialog::get_app_info();
+}
+
+Glib::RefPtr<const Gio::AppInfo> RTAppChooserDialog::get_app_info() const
+{
+    return Gtk::AppChooserDialog::get_app_info();
+}
+
+#else // Work around bugs with GLib and glibmm.
+
+RTAppChooserDialog::RTAppChooserDialog(const Glib::ustring &content_type) :
+    Gtk::AppChooserDialog(content_type)
+{
+    // GTK calls a faulty GLib function to update the most recently selected
+    // application after an application is selected. This removes all signal
+    // handlers to prevent the function call.
+    auto signal_id = g_signal_lookup("response", GTK_TYPE_APP_CHOOSER_DIALOG);
+    while (true) {
+        auto handler_id = g_signal_handler_find(gobj(), G_SIGNAL_MATCH_ID, signal_id, GQuark(), nullptr, nullptr, nullptr);
+        if (!handler_id) {
+            break;
+        }
+        g_signal_handler_disconnect(gobj(), handler_id);
+    }
+}
+
+Glib::RefPtr<Gio::AppInfo> RTAppChooserDialog::get_app_info()
+{
+    // glibmm wrapping of GAppInfo does not work on some platforms. Manually
+    // wrap it here.
+    GAppInfo *gAppInfo = gtk_app_chooser_get_app_info(GTK_APP_CHOOSER(gobj()));
+    return Glib::wrap(gAppInfo, true);
+}
+
+Glib::RefPtr<const Gio::AppInfo> RTAppChooserDialog::get_app_info() const
+{
+    GAppInfo *gAppInfo = gtk_app_chooser_get_app_info(GTK_APP_CHOOSER(
+        const_cast<GtkAppChooserDialog *>(gobj())));
+    return Glib::wrap(gAppInfo, true);
+}
+
+#endif

rtgui/rtappchooserdialog.h

@@ -0,0 +1,39 @@
+/*
+ *  This file is part of RawTherapee.
+ *
+ *  Copyright (c) 2021 Lawrence Lee <billee@ucdavis.edu>
+ *
+ *  RawTherapee is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  RawTherapee is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with RawTherapee.  If not, see <https://www.gnu.org/licenses/>.
+ */
+#pragma once
+
+#include <giomm/appinfo.h>
+#include <glibmm/refptr.h>
+#include <glibmm/ustring.h>
+#include <gtkmm/appchooserdialog.h>
+
+/**
+ * Custom version of gtkmm's Gtk::AppChooserDialog to work around crashes
+ * (https://gitlab.gnome.org/GNOME/glib/-/issues/1104 and
+ * https://gitlab.gnome.org/GNOME/glibmm/-/issues/94).
+ */
+class RTAppChooserDialog : public Gtk::AppChooserDialog
+{
+public:
+    RTAppChooserDialog(const Glib::ustring &content_type);
+    ~RTAppChooserDialog();
+
+    Glib::RefPtr<Gio::AppInfo> get_app_info();
+    Glib::RefPtr<const Gio::AppInfo> get_app_info() const;
+};