# HG changeset patch
# User Torsten Lilge <ttl-octave@mailbox.org>
# Date 1603834124 -3600
# Node ID 8a05763823d164dc446e119881ef5782ec19cbc9
# Parent  b3cd6eb1cca5544f85b66388f16535e282a1e5df
avoid possible infinite loop when default encoding is changed (bug #59331)

* main-window.h, main-window.cc (main_window::notice_settings):
New argument, UPDATE_BY_WORKER.  If true, don't call
update_default_encoding.
(main_window::construct): Update settings_changed/notice_settings
signal/slot connection.
* qt-interpreter-events.h, qt-interpreter-events.cc
(qt_interpreter_events::settings_changed): Update signature of signal
to include bool parameter.
(qt_interpreter_events::gui_preference_slot): Emit settings_changed
with bool parameter set to TRUE.

diff -r b3cd6eb1cca5 -r 8a05763823d1 libgui/src/main-window.cc
--- a/libgui/src/main-window.cc	Wed Oct 28 15:23:30 2020 +0900
+++ b/libgui/src/main-window.cc	Tue Oct 27 22:28:44 2020 +0100
@@ -838,7 +838,8 @@
                         QString::fromStdString (message));
   }
 
-  void main_window::notice_settings (const gui_settings *settings)
+  void main_window::notice_settings (const gui_settings *settings,
+                                     bool update_by_worker)
   {
     if (! settings)
       return;
@@ -927,7 +928,9 @@
     // Check whether some octave internal preferences have to be updated
     QString new_default_encoding
       = settings->value (ed_default_enc).toString ();
-    if (new_default_encoding != m_default_encoding)
+    // Do not update internal pref only if a) this update was not initiated
+    // by the worker and b) the pref has really changes
+    if (! update_by_worker && (new_default_encoding != m_default_encoding))
       update_default_encoding (new_default_encoding);
 
     // Set cursor blinking depending on the settings
@@ -2169,8 +2172,8 @@
 
     qt_interpreter_events *qt_link = interp_qobj->qt_link ();
 
-    connect (qt_link, SIGNAL (settings_changed (const gui_settings *)),
-             this, SLOT (notice_settings (const gui_settings *)));
+    connect (qt_link, SIGNAL (settings_changed (const gui_settings *, bool)),
+             this, SLOT (notice_settings (const gui_settings *, bool)));
 
     connect (qt_link, SIGNAL (apply_new_settings (void)),
              this, SLOT (request_reload_settings (void)));
diff -r b3cd6eb1cca5 -r 8a05763823d1 libgui/src/main-window.h
--- a/libgui/src/main-window.h	Wed Oct 28 15:23:30 2020 +0900
+++ b/libgui/src/main-window.h	Tue Oct 27 22:28:44 2020 +0100
@@ -157,7 +157,8 @@
                                           = QString ());
 
     void show_about_octave (void);
-    void notice_settings (const gui_settings *settings);
+    void notice_settings (const gui_settings *settings,
+                          bool update_by_worker = false);
     void prepare_to_exit (void);
     void go_to_previous_widget (void);
     void reset_windows (void);
diff -r b3cd6eb1cca5 -r 8a05763823d1 libgui/src/qt-interpreter-events.cc
--- a/libgui/src/qt-interpreter-events.cc	Wed Oct 28 15:23:30 2020 +0900
+++ b/libgui/src/qt-interpreter-events.cc	Tue Oct 27 22:28:44 2020 +0100
@@ -601,7 +601,7 @@
         // Change settings only for new, non-empty values
         settings->setValue (key, QVariant (adjusted_value));
 
-        emit settings_changed (settings);
+        emit settings_changed (settings, true);   // true: changed by worker
       }
 
     m_result = read_value;
diff -r b3cd6eb1cca5 -r 8a05763823d1 libgui/src/qt-interpreter-events.h
--- a/libgui/src/qt-interpreter-events.h	Wed Oct 28 15:23:30 2020 +0900
+++ b/libgui/src/qt-interpreter-events.h	Tue Oct 27 22:28:44 2020 +0100
@@ -248,7 +248,7 @@
 
     void get_named_icon_signal (const QString& name);
 
-    void settings_changed (const gui_settings *);
+    void settings_changed (const gui_settings *, bool);
 
     void apply_new_settings (void);