1 files changed, 11 insertions, 2 deletions

diff --git a/src/keyboard.c b/src/keyboard.c
index 91faf4582fa..a06c9116d24 100644
--- a/src/keyboard.c
+++ b/src/keyboard.c
@@ -6639,8 +6639,17 @@ make_lispy_event (struct input_event *event)
 
         if (CONSP (event->arg))
           return list5 (head, position, make_fixnum (double_click_count),
-                        XCAR (event->arg), Fcons (XCAR (XCDR (event->arg)),
-                                                  XCAR (XCDR (XCDR (event->arg)))));
+                        XCAR (event->arg),
+                        /* FIXME: When a mouse-click on a tab-bar is
+                           converted into a wheel-event we get here something
+                           of an unexpected shape...  */
+                        (CONSP (XCDR (event->arg))
+                         && CONSP (XCDR (XCDR (event->arg))))
+                        ? Fcons (XCAR (XCDR (event->arg)),
+                                 XCAR (XCDR (XCDR (event->arg))))
+                        /* ... not knowing what this "unexpected shape" means,
+                           we just use nil.  */
+                        : Qnil);
         else if (NUMBERP (event->arg))
           return list4 (head, position, make_fixnum (double_click_count),
                         event->arg);