1 files changed, 21 insertions, 0 deletions
diff --git a/src/shared/ptyfwd.c b/src/shared/ptyfwd.c
index 3a02ae98dc..59b541d519 100644
--- a/src/shared/ptyfwd.c
+++ b/src/shared/ptyfwd.c
@@ -69,6 +69,7 @@ struct PTYForward {
         bool read_from_master:1;
 
         bool done:1;
+        bool drain:1;
 
         bool last_char_set:1;
         char last_char;
@@ -302,6 +303,11 @@ static int shovel(PTYForward *f) {
                         return pty_forward_done(f, 0);
         }
 
+        /* If we were asked to drain, and there's nothing more to handle from the master, then call the callback
+         * too. */
+        if (f->drain && f->out_buffer_full == 0 && !f->master_readable)
+                return pty_forward_done(f, 0);
+
         return 0;
 }
 
@@ -528,3 +534,18 @@ void pty_forward_set_handler(PTYForward *f, PTYForwardHandler cb, void *userdata
         f->handler = cb;
         f->userdata = userdata;
 }
+
+bool pty_forward_drain(PTYForward *f) {
+        assert(f);
+
+        /* Starts draining the forwarder. Specifically:
+         *
+         * - Returns true if there are no unprocessed bytes from the pty, false otherwise
+         *
+         * - Makes sure the handler function is called the next time the number of unprocessed bytes hits zero
+         */
+
+        f->drain = true;
+
+        return f->out_buffer_full == 0 && !f->master_readable;
+}