From d1e0545323cdb07d1ed46a80dbcbe509bdfbe1ea Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Gerd=20M=C3=B6llmann?= <gerd@gnu.org>
Date: Fri, 19 Apr 2024 14:59:12 +0200
Subject: [PATCH] Root for last_nonminibuffer_frame

---
 src/frame.c |  4 ++++
 src/igc.c   | 21 +++++++++++++++++++++
 src/igc.h   |  1 +
 3 files changed, 26 insertions(+)

diff --git a/src/frame.c b/src/frame.c
index ff99b0353af..42fb8eccb46 100644
--- a/src/frame.c
+++ b/src/frame.c
@@ -27,6 +27,7 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 #include <c-ctype.h>
 
 #include "lisp.h"
+#include "igc.h"
 
 #ifdef HAVE_WINDOW_SYSTEM
 #include TERM_HEADER
@@ -6257,6 +6258,9 @@ init_frame_once_for_pdumper (void)
 {
   PDUMPER_RESET_LV (Vframe_list, Qnil);
   PDUMPER_RESET_LV (selected_frame, Qnil);
+#ifdef HAVE_MPS
+  igc_root_create_exact_ptr (&last_nonminibuf_frame);
+#endif
 }
 
 void
diff --git a/src/igc.c b/src/igc.c
index 794f5b9507b..ff1df006eb7 100644
--- a/src/igc.c
+++ b/src/igc.c
@@ -838,6 +838,19 @@ scan_exact (mps_ss_t ss, void *start, void *end, void *closure)
   return MPS_RES_OK;
 }
 
+static mps_res_t
+scan_ptr_exact (mps_ss_t ss, void *start, void *end, void *closure)
+{
+  MPS_SCAN_BEGIN (ss)
+  {
+    for (void **p = start; (void *) p < end; ++p)
+      if (*p)
+	IGC_FIX12_RAW (ss, p);
+  }
+  MPS_SCAN_END (ss);
+  return MPS_RES_OK;
+}
+
 /***********************************************************************
 			 Default pad, fwd, ...
  ***********************************************************************/
@@ -1644,6 +1657,14 @@ igc_root_create_exact (Lisp_Object *start, Lisp_Object *end)
   root_create_exact (global_igc, start, end, scan_exact);
 }
 
+void
+igc_root_create_exact_ptr (void *var_addr)
+{
+  void *start = var_addr;
+  void *end = (char *) start + sizeof (void *);
+  root_create_exact (global_igc, start, end, scan_ptr_exact);
+}
+
 static void
 root_create_specpdl (struct igc_thread_list *t)
 {
diff --git a/src/igc.h b/src/igc.h
index 39ce15ee8f1..eae268b49e7 100644
--- a/src/igc.h
+++ b/src/igc.h
@@ -92,6 +92,7 @@ void igc_check_symbol (void *p);
 void igc_collect (void);
 void igc_root_create_ambig (void *start, void *end);
 void igc_root_create_exact (Lisp_Object *start, Lisp_Object *end);
+void igc_root_create_exact_ptr (void *var_addr);
 
 # define eassert_not_mps() eassert (false)
 #else