livecode · livecodepanos · Oct 9, 2019 · Sep 15, 2019 · Oct 3, 2019 · Oct 3, 2019
diff --git a/docs/notes/bugfix-22130.md b/docs/notes/bugfix-22130.md
@@ -0,0 +1 @@
+# Improve stability of breakpoint manipulation in the S/E whilst debugging
diff --git a/engine/src/debug.cpp b/engine/src/debug.cpp
@@ -285,7 +285,9 @@ void MCB_prepmessage(MCExecContext &ctxt, MCNameRef mess, uint2 line, uint2 pos,
 		p3.setnext(&p4);
 		p4.setvalueref_argument(p_info);
 	}
-	MCB_message(ctxt, mess, &p1);
+    MCDeletedObjectsFreezePool();
+    MCB_message(ctxt, mess, &p1);
+    MCDeletedObjectsThawPool();
 	if (id != 0)
 		MCeerror->clear();
 	if (added)

diff --git a/engine/src/object.cpp b/engine/src/object.cpp
@@ -5523,6 +5523,7 @@ struct MCDeletedObjectPool
 static MCDeletedObjectPool *MCsparedeletedobjectpool = nil;
 static MCDeletedObjectPool *MCdeletedobjectpool = nil;
 static MCDeletedObjectPool *MCrootdeletedobjectpool = nil;
+static uint32_t MCdeletedobjectpoolfreezedepth = 0;
 
 static bool MCDeletedObjectPoolCreate(MCDeletedObjectPool*& r_pool)
 {
@@ -5608,8 +5609,22 @@ void MCDeletedObjectsTeardown(void)
     }
 }
 
+void MCDeletedObjectsFreezePool(void)
+{
+    MCdeletedobjectpoolfreezedepth += 1;
+}
+
+void MCDeletedObjectsThawPool(void)
+{    
+    MCdeletedobjectpoolfreezedepth -= 1;
+}
+
 void MCDeletedObjectsEnterWait(bool p_dispatching)
 {
+    // If the current pool is frozen, do nothing
+    if (MCdeletedobjectpoolfreezedepth > 0)
+        return;
+
     // If this isn't a dispatching wait, then no objects can be created.
     if (!p_dispatching)
         return;
@@ -5636,6 +5651,10 @@ void MCDeletedObjectsEnterWait(bool p_dispatching)
 
 void MCDeletedObjectsLeaveWait(bool p_dispatching)
 {
+    // If the current pool is frozen, do nothing
+    if (MCdeletedobjectpoolfreezedepth > 0)
+        return;
+
     // If this isn't a dispatching wait, then no objects can be created.
     if (!p_dispatching)
         return;

diff --git a/engine/src/object.h b/engine/src/object.h
@@ -506,6 +506,8 @@ struct MCExecValue;
 struct MCDeletedObjectPool;
 void MCDeletedObjectsSetup(void);
 void MCDeletedObjectsTeardown(void);
+void MCDeletedObjectsFreezePool(void);
+void MCDeletedObjectsThawPool(void);
 void MCDeletedObjectsEnterWait(bool p_dispatching);
 void MCDeletedObjectsLeaveWait(bool p_dispatching);
 void MCDeletedObjectsOnObjectCreated(MCObject *object);
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1 @@
		# Improve stability of breakpoint manipulation in the S/E whilst debugging