(x_get_arg): Clear out all occurrences of PARAM in ALIST.

1 files changed, 7 insertions, 0 deletions

diff --git a/src/frame.c b/src/frame.c
index 6712fa6b287..08b3764fe16 100644
--- a/src/frame.c
+++ b/src/frame.c
@@ -3526,7 +3526,14 @@ x_get_arg (dpyinfo, alist, param, attribute, class, type)
          so that it won't be "left over" at the end.  */
 #ifdef HAVE_X_WINDOWS /* macfns.c and w32fns.c have not yet
                          been changed to cope with this.  */
+      Lisp_Object tail;
       XSETCAR (tem, Qnil);
+      /* In case the parameter appears more than once in the alist,
+         clear it out.  */
+      for (tail = alist; CONSP (tail); tail = XCDR (tail))
+        if (CONSP (XCAR (tail))
+            && EQ (XCAR (XCAR (tail)), param))
+          XSETCAR (XCAR (tail), Qnil);
 #endif
     }
   else