Handle xwidgets like processes and delete them when their buffer is killed.

* lisp/xwidget.el (xwidget-kill-buffer-query-function): New function to
query a user before killing a buffer with xwidgets in it.

This function is stored in `kill-buffer-query-functions' and called from
`kill-buffer'.
* src/buffer.c (Fkill_buffer): Call `kill_buffer_xwidgets'.
* src/xwidget.c (kill_buffer_xwidgets): Delete xwidgets attached to the
specified buffer.
* src/xwidget.h (kill_buffer_xwidgets): Add definition.

1 files changed, 9 insertions, 0 deletions

diff --git a/src/buffer.c b/src/buffer.c
index abebdf21135..4e0dbe778ef 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -44,6 +44,10 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include "keymap.h"
 #include "frame.h"
 
+#ifdef HAVE_XWIDGETS
+#include "xwidget.h"
+#endif  /* HAVE_XWIDGETS */
+
 struct buffer *current_buffer;          /* The current buffer.  */
 
 /* First buffer in chain of all buffers (in reverse order of creation).
@@ -1835,6 +1839,11 @@ cleaning up all windows currently displaying the buffer to be killed. */)
   kill_buffer_processes (buffer);
   UNGCPRO;
 
+#ifdef HAVE_XWIDGETS
+  GCPRO1 (buffer);
+  kill_buffer_xwidgets (buffer);
+  UNGCPRO;
+#endif  /* HAVE_XWIDGETS */
   /* Killing buffer processes may run sentinels which may have killed
      our buffer.  */
   if (!BUFFER_LIVE_P (b))