PR python/17372 - Python hangs when displaying help()

[deliverable/binutils-gdb.git] / gdb / infrun.c

diff --git a/gdb/infrun.c b/gdb/infrun.c
index 7af5e0f58c3fcf84c594a1858e383f659cfa3ed9..e25f392fd989dea768ea01e8801abc0dc4711f80 100644 (file)
--- a/gdb/infrun.c
+++ b/gdb/infrun.c
@@ -3107,6 +3107,23 @@ wait_for_inferior (void)
   do_cleanups (old_cleanups);
 }
 
+/* Cleanup that reinstalls the readline callback handler, if the
+   target is running in the background.  If while handling the target
+   event something triggered a secondary prompt, like e.g., a
+   pagination prompt, we'll have removed the callback handler (see
+   gdb_readline_wrapper_line).  Need to do this as we go back to the
+   event loop, ready to process further input.  Note this has no
+   effect if the handler hasn't actually been removed, because calling
+   rl_callback_handler_install resets the line buffer, thus losing
+   input.  */
+
+static void
+reinstall_readline_callback_handler_cleanup (void *arg)
+{
+  if (async_command_editing_p && !sync_execution)
+    gdb_rl_callback_handler_reinstall ();
+}
+
 /* Asynchronous version of wait_for_inferior.  It is called by the
    event loop whenever a change of state is detected on the file
    descriptor corresponding to the target.  It can be called more than
@@ -3129,6 +3146,9 @@ fetch_inferior_event (void *client_data)
 
   memset (ecs, 0, sizeof (*ecs));
 
+  /* End up with readline processing input, if necessary.  */
+  make_cleanup (reinstall_readline_callback_handler_cleanup, NULL);
+
   /* We're handling a live event, so make sure we're doing live
      debugging.  If we're looking at traceframes while the target is
      running, we're going to need to get back to that mode after