Merge branch 'gtk-log'

Fix crash when using wxNotebook in applications calling
g_log_set_writer_func() with glib 2.73+

See #22753.

include/wx/gtk/app.h

@@ -59,11 +59,18 @@ public:
     static bool GTKIsUsingGlobalMenu();
 
     // Provide the ability to suppress GTK output. By default, all output
-    // will be suppressed, but the user can pass in a mask specifiyng the
+    // will be suppressed, but the user can pass in a mask specifying the
     // types of messages to suppress. Flags are defined by glib with the
     // GLogLevelFlags enum.
     static void GTKSuppressDiagnostics(int flags = -1);
 
+    // Allow wxWidgets to control GTK diagnostics. This is recommended because
+    // it prevents spurious GTK messages from appearing, but can't be done by
+    // default because it would result in a fatal error if the application
+    // calls g_log_set_writer_func() itself.
+    static void GTKAllowDiagnosticsControl();
+
+
     // implementation only from now on
     // -------------------------------
 

include/wx/gtk/private/log.h

@@ -33,7 +33,14 @@ public:
         m_next = NULL;
     }
 
-    // Function to call to install this filter as the active one.
+    // Allow installing our own log writer function, we don't do it by default
+    // because this results in a fatal error if the application had already
+    // called g_log_set_writer_func() on its own.
+    static void Allow() { ms_allowed = true; }
+
+    // Function to call to install this filter as the active one if we're
+    // allowed to do this, i.e. if Allow() had been called before.
+    //
     // Does nothing and just returns false if run-time glib version is too old.
     bool Install();
 
@@ -56,6 +63,10 @@ private:
                   gsize            n_fields,
                   gpointer         user_data);
 
+    // False initially, indicating that we're not allowed to install our own
+    // logging function.
+    static bool ms_allowed;
+
     // False initially, set to true when we install wx_log_writer() as the log
     // writer. Once we do it, we never change it any more.
     static bool ms_installed;

interface/wx/app.h

@@ -1061,6 +1061,25 @@ public:
     */
     static void GTKSuppressDiagnostics(int flags = -1);
 
+    /**
+        Allows wxWidgets to selectively suppress some GTK messages.
+
+        This function can be called to allow wxWidgets to control GTK message
+        logging. You must @e not call it if your application calls the @c
+        g_log_set_writer_func() function itself, as this function can be only
+        called once.
+
+        It is recommended to call this function in your overridden version of
+        wxApp::OnInit() to allow wxWidgets to suppress some spurious GTK error
+        messages, e.g. the ones that happen whenever wxNotebook pages are
+        removed with the current GTK versions.
+
+        @onlyfor{wxgtk}
+
+        @since 3.2.1
+     */
+    static void GTKAllowDiagnosticsControl();
+
     ///@}
 
     /**

interface/wx/notebook.h

@@ -145,6 +145,10 @@ public:
 
     /**
         Destroys the wxNotebook object.
+
+        @note When using wxGTK, destroying notebook can result in spurious GTK
+        diagnostic messages, you may use wxApp::GTKAllowDiagnosticsControl() to
+        suppress them.
     */
     virtual ~wxNotebook();
 

samples/notebook/notebook.cpp

@@ -37,6 +37,13 @@ bool MyApp::OnInit()
     if ( !wxApp::OnInit() )
         return false;
 
+#ifdef __WXGTK__
+    // Many version of wxGTK generate spurious diagnostic messages when
+    // destroying wxNotebook (or removing pages from it), allow wxWidgets to
+    // suppress them.
+    GTKAllowDiagnosticsControl();
+#endif // __WXGTK__
+
 #if wxUSE_HELP
     wxHelpProvider::Set( new wxSimpleHelpProvider );
 #endif
@@ -329,7 +336,7 @@ MyFrame::MyFrame()
 #endif
     menuType->AppendRadioItem(ID_BOOK_SIMPLEBOOK, "&Simple book\tCtrl-7");
 
-    menuType->Check(ID_BOOK_NOTEBOOK + m_type, true);
+    menuType->Check(static_cast<int>(ID_BOOK_NOTEBOOK) + m_type, true);
 
     wxMenu *menuOrient = new wxMenu;
     menuOrient->AppendRadioItem(ID_ORIENT_DEFAULT, "&Default\tAlt-0");

src/gtk/app.cpp

@@ -184,6 +184,7 @@ bool wxApp::DoIdle()
 namespace wxGTKImpl
 {
 
+bool LogFilter::ms_allowed = false;
 bool LogFilter::ms_installed = false;
 LogFilter* LogFilter::ms_first = NULL;
 
@@ -205,6 +206,9 @@ LogFilter::wx_log_writer(GLogLevelFlags   log_level,
 
 bool LogFilter::Install()
 {
+    if ( !ms_allowed )
+        return false;
+
     if ( !ms_installed )
     {
         if ( glib_check_version(2, 50, 0) != 0 )
@@ -278,12 +282,24 @@ void wxApp::GTKSuppressDiagnostics(int flags)
     s_logFilter.SetLevelToIgnore(flags);
     s_logFilter.Install();
 }
+
+/* static */
+void wxApp::GTKAllowDiagnosticsControl()
+{
+    wxGTKImpl::LogFilter::Allow();
+}
 #else // !wxHAS_GLIB_LOG_WRITER
 /* static */
 void wxApp::GTKSuppressDiagnostics(int WXUNUSED(flags))
 {
     // We can't do anything here.
 }
+
+/* static */
+void wxApp::GTKAllowDiagnosticsControl()
+{
+    // And don't need to do anything here.
+}
 #endif // wxHAS_GLIB_LOG_WRITER/!wxHAS_GLIB_LOG_WRITER
 
 //-----------------------------------------------------------------------------