Fix freezing with scroll bars of GTK3 Toolkit.

* src/keyboard.c (unblock_input): Add comment.
* src/xgselect.c (xg_select): Prevent Glib main loop recursion.

Fixes: debbugs:15801

1 files changed, 6 insertions, 1 deletions

diff --git a/src/keyboard.c b/src/keyboard.c
index 1f4b23d9905..90479375072 100644
--- a/src/keyboard.c
+++ b/src/keyboard.c
@@ -7121,7 +7121,12 @@ unblock_input_to (int level)
 /* End critical section.
 
    If doing signal-driven input, and a signal came in when input was
-   blocked, reinvoke the signal handler now to deal with it.  */
+   blocked, reinvoke the signal handler now to deal with it.
+
+   It will also process queued input, if it was not read before.
+   When a longer code sequence does not use block/unblock input
+   at all, the whole input gathered up to the next call to
+   unblock_input will be processed inside that call. */
 
 void
 unblock_input (void)