Fix: crash on connect - invalid VTE signal 'size-changed'

The signal 'size-changed' does not exist in VTE 2.91. This caused a
GLib-GObject-CRITICAL warning followed by a segfault when connecting.

Fixed by replacing the VTE signal with GTK's 'size-allocate' signal
on the terminal widget, which correctly detects terminal size changes
and resizes the remote PTY accordingly.

src/ssh_terminal.cpp

@@ -17,7 +17,7 @@ SshTerminal::SshTerminal()
 	gtk_box_pack_start(GTK_BOX(vte_box_), GTK_WIDGET(terminal_), TRUE, TRUE, 0);
 	gtk_widget_show_all(vte_box_);
 
-	g_signal_connect(terminal_, "size-changed", G_CALLBACK(on_size_changed), this);
+	g_signal_connect(terminal_, "size-allocate", G_CALLBACK(on_size_changed), this);
 }
 
 SshTerminal::~SshTerminal() {
@@ -28,10 +28,13 @@ SshTerminal::~SshTerminal() {
 	}
 }
 
-void SshTerminal::on_size_changed(VteTerminal* term, guint cols, guint rows, gpointer data) {
-	(void)term;
+void SshTerminal::on_size_changed(GtkWidget* widget, GtkAllocation* alloc, gpointer data) {
+	(void)alloc;
 	auto* self = static_cast<SshTerminal*>(data);
 	if (self->channel_ && self->connected_) {
+		VteTerminal* term = VTE_TERMINAL(widget);
+		guint cols = vte_terminal_get_column_count(term);
+		guint rows = vte_terminal_get_row_count(term);
 		ssh_channel_change_pty_size(self->channel_, cols, rows);
 	}
 }

src/ssh_terminal.h

@@ -25,7 +25,7 @@ public:
 private:
 	void cleanup();
 	static gpointer io_thread_func(gpointer data);
-	static void on_size_changed(VteTerminal* term, guint cols, guint rows, gpointer data);
+	static void on_size_changed(GtkWidget* widget, GtkAllocation* alloc, gpointer data);
 
 	GtkWidget* vte_box_;
 	VteTerminal* terminal_;