Implement selection ownership on Haiku

* lisp/term/haiku-win.el (haiku-selection-owner-p): New
declaration.
(gui-backend-selection-owner-p): Implement using newly exposed
primitive.

* src/haiku_select.cc
(count_clipboard, count_primary, count_secondary): New
variables for tracking selection ownership.
(BClipboard_set_system_data):
(BClipboard_set_primary_selection_data):
(BClipboard_set_secondary_selection_data): Set ownership
variables.
(BClipboard_owns_clipboard):
(BClipboard_owns_primary):
(BClipboard_owns_secondary): New functions.

* src/haikuselect.c (Fhaiku_selection_owner_p): New function.
(syms_of_haikuselect): Define new subr.
* src/haikuselect.h: New prototypes.

1 files changed, 3 insertions, 3 deletions

diff --git a/lisp/term/haiku-win.el b/lisp/term/haiku-win.el
index 739ea9fdfce..a5cde929f96 100644
--- a/lisp/term/haiku-win.el
+++ b/lisp/term/haiku-win.el
@@ -50,6 +50,7 @@
 (declare-function haiku-selection-data "haikuselect.c")
 (declare-function haiku-selection-put "haikuselect.c")
 (declare-function haiku-selection-targets "haikuselect.c")
+(declare-function haiku-selection-owner-p "haikuselect.c")
 (declare-function haiku-put-resource "haikufns.c")
 
 (defun haiku--handle-x-command-line-resources (command-line-resources)
@@ -105,9 +106,8 @@ If TYPE is nil, return \"text/plain\"."
                                               &context (window-system haiku))
   (haiku-selection-data selection "text/plain"))
 
-(cl-defmethod gui-backend-selection-owner-p (_
-                                             &context (window-system haiku))
-  t)
+(cl-defmethod gui-backend-selection-owner-p (selection &context (window-system haiku))
+  (haiku-selection-owner-p selection))
 
 (declare-function haiku-read-file-name "haikufns.c")