Don't touch window title before an OSC is received.

Fixes the "window title being clobbered" issue raised in issue 137.

Signed-off-by: sqweek <sqweek@gmail.com>

Closes #380. Closes #137.

src/terminal/terminalframebuffer.h

@@ -248,6 +248,7 @@ namespace Terminal {
     std::deque<wchar_t> icon_name;
     std::deque<wchar_t> window_title;
     unsigned int bell_count;
+    bool title_initialized; /* true if the window title has been set via an OSC */
 
     Row newrow( void ) { return Row( ds.get_width(), ds.get_background_rendition() ); }
 
@@ -311,6 +312,8 @@ namespace Terminal {
     void reset( void );
     void soft_reset( void );
 
+    void set_title_initialized( void ) { title_initialized = true; }
+    bool is_title_initialized( void ) const { return title_initialized; }
     void set_icon_name( const std::deque<wchar_t> &s ) { icon_name = s; }
     void set_window_title( const std::deque<wchar_t> &s ) { window_title = s; }
     const std::deque<wchar_t> & get_icon_name( void ) const { return icon_name; }