Fix bug#30846, along with misc cleanups found along the way

* test/src/data-tests.el (data-tests-kill-all-local-variables): New test.

* src/buffer.c (swap_out_buffer_local_variables): Remove.
Fuse the body of its loop into that of reset_buffer_local_variables.
(Fkill_buffer, Fkill_all_local_variables): Don't call it any more.
(reset_buffer_local_variables): Make sure the buffer's local binding
is swapped out before removing it from the alist (bug#30846).
Call watchers before actually killing the var.

* src/data.c (Fmake_local_variable): Simplify.
Use swap_in_global_binding to swap out any local binding, instead of
a mix of find_symbol_value followed by messing with where&found.
Don't call swap_in_symval_forwarding since the currently swapped
binding is never one we've modified.
(Fkill_local_variable): Use swap_in_global_binding rather than messing
with where&found to try and trick find_symbol_value into doing the same.

* src/alloc.c (mark_localized_symbol): 'where' can't be a frame any more.

1 files changed, 2 insertions, 6 deletions

diff --git a/src/alloc.c b/src/alloc.c
index 5eaf7cbc1c6..369592d70ee 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -6342,12 +6342,8 @@ mark_localized_symbol (struct Lisp_Symbol *ptr)
 {
   struct Lisp_Buffer_Local_Value *blv = SYMBOL_BLV (ptr);
   Lisp_Object where = blv->where;
-  /* If the value is set up for a killed buffer or deleted
-     frame, restore its global binding.  If the value is
-     forwarded to a C variable, either it's not a Lisp_Object
-     var, or it's staticpro'd already.  */
-  if ((BUFFERP (where) && !BUFFER_LIVE_P (XBUFFER (where)))
-      || (FRAMEP (where) && !FRAME_LIVE_P (XFRAME (where))))
+  /* If the value is set up for a killed buffer restore its global binding.  */
+  if ((BUFFERP (where) && !BUFFER_LIVE_P (XBUFFER (where))))
     swap_in_global_binding (ptr);
   mark_object (blv->where);
   mark_object (blv->valcell);