mosh-server: Fix bug where spins forever if process dies while disconnected

src/network/transportsender.cc

@@ -56,6 +56,7 @@ TransportSender<MyState>::TransportSender( Connection *s_connection, MyState &in
     verbose( false ),
     shutdown_in_progress( false ),
     shutdown_tries( 0 ),
+    shutdown_start( -1 ),
     ack_num( 0 ),
     pending_data_ack( false ),
     SEND_MINDELAY( 8 ),
@@ -357,7 +358,15 @@ void TransportSender<MyState>::process_acknowledgment_through( uint64_t ack_num
 template <class MyState>
 bool TransportSender<MyState>::shutdown_ack_timed_out( void ) const
 {
-  return shutdown_tries >= SHUTDOWN_RETRIES;
+  if ( shutdown_in_progress ) {
+    if ( shutdown_tries >= SHUTDOWN_RETRIES ) {
+      return true;
+    } else if ( timestamp() - shutdown_start >= uint64_t( ACTIVE_RETRY_TIMEOUT ) ) {
+      return true;
+    }
+  }
+
+  return false;
 }
 
 /* Executed upon entry to new receiver state */

src/network/transportsender.h

@@ -94,6 +94,7 @@ namespace Network {
     bool verbose;
     bool shutdown_in_progress;
     int shutdown_tries;
+    uint64_t shutdown_start;
 
     /* information about receiver state */
     uint64_t ack_num;
@@ -132,7 +133,7 @@ namespace Network {
     void remote_heard( uint64_t ts ) { last_heard = ts; }
 
     /* Starts shutdown sequence */
-    void start_shutdown( void ) { shutdown_in_progress = true; }
+    void start_shutdown( void ) { if ( !shutdown_in_progress ) { shutdown_start = timestamp(); shutdown_in_progress = true; } }
 
     /* Misc. getters and setters */
     /* Cannot modify current_state while shutdown in progress */