Show infobar when Ctrl-^ is typed.

src/frontend/stmclient.cc

@@ -255,6 +255,8 @@ bool STMClient::process_user_input( int fd )
 
       overlays.get_prediction_engine().new_user_byte( the_byte, *local_framebuffer );
 
+      const static wstring help_message( L"Commands: Ctrl-Z suspends, \".\" quits, \"^\" gives literal Ctrl-^" );
+
       if ( quit_sequence_started ) {
 	if ( the_byte == '.' ) { /* Quit sequence is Ctrl-^ . */
 	  if ( network->has_remote_addr() && (!network->shutdown_in_progress()) ) {
@@ -291,11 +293,17 @@ bool STMClient::process_user_input( int fd )
 	}
 
 	quit_sequence_started = false;
+
+	if ( overlays.get_notification_engine().get_notification_string() == help_message ) {
+	  overlays.get_notification_engine().set_notification_string( L"" );
+	}
+
 	continue;
       }
 
       quit_sequence_started = (the_byte == 0x1E);
       if ( quit_sequence_started ) {
+	overlays.get_notification_engine().set_notification_string( help_message, true, false );
 	continue;
       }
 

src/frontend/terminaloverlay.cc

@@ -168,7 +168,8 @@ NotificationEngine::NotificationEngine()
     last_acked_state( timestamp() ),
     message(),
     message_is_network_exception( false ),
-    message_expiration( -1 )
+    message_expiration( -1 ),
+    show_quit_keystroke( true )
 {}
 
 static std::string human_readable_duration( int num_seconds, const std::string seconds_abbr ) {
@@ -232,16 +233,22 @@ void NotificationEngine::apply( Framebuffer &fb ) const
     explanation = reply_message;
   }
 
+  const static char quit_keystroke[] = " [To quit: Ctrl-^ .]";
+  const static char blank[] = "";
+
+  const char *keystroke_str = show_quit_keystroke ? quit_keystroke : blank;
+
   if ( message.empty() && (!time_expired) ) {
     return;
   } else if ( message.empty() && time_expired ) {
-    swprintf( tmp, 128, L"mosh: Last %s %s ago. [To quit: Ctrl-^ .]", explanation,
-	      human_readable_duration( time_elapsed, "seconds" ).c_str() );
+    swprintf( tmp, 128, L"mosh: Last %s %s ago.%s", explanation,
+	      human_readable_duration( time_elapsed, "seconds" ).c_str(),
+	      keystroke_str );
   } else if ( (!message.empty()) && (!time_expired) ) {
-    swprintf( tmp, 128, L"mosh: %ls [To quit: Ctrl-^ .]", message.c_str() );
+    swprintf( tmp, 128, L"mosh: %ls%s", message.c_str(), keystroke_str );
   } else {
-    swprintf( tmp, 128, L"mosh: %ls (%s without %s.) [To quit: Ctrl-^ .]", message.c_str(),
-	      human_readable_duration( time_elapsed, "s" ).c_str(), explanation );
+    swprintf( tmp, 128, L"mosh: %ls (%s without %s.)%s", message.c_str(),
+	      human_readable_duration( time_elapsed, "s" ).c_str(), explanation, keystroke_str );
   }
 
   wstring string_to_draw( tmp );

src/frontend/terminaloverlay.h

@@ -147,6 +147,7 @@ namespace Overlay {
     wstring message;
     bool message_is_network_exception;
     uint64_t message_expiration;
+    bool show_quit_keystroke;
 
     bool server_late( uint64_t ts ) const { return (ts - last_word_from_server) > 6500; }
     bool reply_late( uint64_t ts ) const { return (ts - last_acked_state) > 10000; }
@@ -160,7 +161,7 @@ namespace Overlay {
     void server_acked( uint64_t s_last_acked ) { last_acked_state = s_last_acked; }
     int wait_time( void ) const;
 
-    void set_notification_string( const wstring &s_message, bool permanent = false )
+    void set_notification_string( const wstring &s_message, bool permanent = false, bool s_show_quit_keystroke = true )
     {
       message = s_message;
       if ( permanent ) {
@@ -169,6 +170,7 @@ namespace Overlay {
         message_expiration = timestamp() + 1000;
       }
       message_is_network_exception = false;
+      show_quit_keystroke = s_show_quit_keystroke;
     }
 
     void set_network_exception( const NetworkException &e )