Update the MULTIPLE property with conversion outcomes

Per the ICCCM spec:

> If the owner fails to convert the target named by an atom in the
> MULTIPLE property, it should replace that atom in the property with
> None.

* src/xselect.c (x_handle_selection_request): Do it.

1 files changed, 11 insertions, 2 deletions

diff --git a/src/xselect.c b/src/xselect.c
index 537be2ddd54..f2a64dd9534 100644
--- a/src/xselect.c
+++ b/src/xselect.c
@@ -795,6 +795,7 @@ x_handle_selection_request (struct selection_input_event *event)
       Window requestor = SELECTION_EVENT_REQUESTOR (event);
       Lisp_Object multprop;
       ptrdiff_t j, nselections;
+      struct selection_data cs;
 
       if (property == None) goto DONE;
       multprop
@@ -811,11 +812,19 @@ x_handle_selection_request (struct selection_input_event *event)
           Lisp_Object subtarget = AREF (multprop, 2*j);
           Atom subproperty = symbol_to_x_atom (dpyinfo,
                                                AREF (multprop, 2*j+1));
+          bool subsuccess = false;
 
           if (subproperty != None)
-            x_convert_selection (selection_symbol, subtarget,
-                                 subproperty, true, dpyinfo);
+            subsuccess = x_convert_selection (selection_symbol, subtarget,
+                                              subproperty, true, dpyinfo);
+          if (!subsuccess)
+            ASET (multprop, 2*j+1, Qnil);
         }
+      /* Save conversion results */
+      lisp_data_to_selection_data (dpyinfo, multprop, &cs);
+      XChangeProperty (dpyinfo->display, requestor, property,
+                       cs.type, cs.format, PropModeReplace,
+                       cs.data, cs.size);
       success = true;
     }
   else