cleanup: skip a do_gc iteration before removing peers marked for deletion

This fixes an issue with events where we try to make queries on peers
that no longer exist internally

Author: JFreegman

other/bootstrap_daemon/docker/tox-bootstrapd.sha256

@@ -1 +1 @@
-0b58b866f87d92267db4577d26eebe10dcf5a96ff53ac5a863dade83f471961c  /usr/local/bin/tox-bootstrapd
+738c98673260593fc150b8d5b0cb770cd521f469b4eb04c873f19d89bb7238cf  /usr/local/bin/tox-bootstrapd

toxcore/group_chats.c

@@ -6995,23 +6995,30 @@ non_null(1, 2) nullable(3)
 static void do_peer_delete(const GC_Session *c, GC_Chat *chat, void *userdata)
 {
     for (uint32_t i = 1; i < chat->numpeers; ++i) {
-        const GC_Connection *gconn = get_gc_connection(chat, i);
+        GC_Connection *gconn = get_gc_connection(chat, i);
         assert(gconn != nullptr);
 
-        if (gconn->pending_delete) {
-            const GC_Exit_Info *exit_info = &gconn->exit_info;
+        if (!gconn->pending_delete) {
+            continue;
+        }
 
-            if (exit_info->exit_type == GC_EXIT_TYPE_TIMEOUT && gconn->confirmed) {
-                add_gc_peer_timeout_list(chat, gconn);
-            }
+        if (!gconn->delete_this_iteration) {
+            gconn->delete_this_iteration = true;
+            continue;
+        }
 
-            if (!peer_delete(c, chat, i, userdata)) {
-                LOGGER_ERROR(chat->log, "Failed to delete peer %u", i);
-            }
+        const GC_Exit_Info *exit_info = &gconn->exit_info;
 
-            if (i >= chat->numpeers) {
-                break;
-            }
+        if (exit_info->exit_type == GC_EXIT_TYPE_TIMEOUT && gconn->confirmed) {
+            add_gc_peer_timeout_list(chat, gconn);
+        }
+
+        if (!peer_delete(c, chat, i, userdata)) {
+            LOGGER_ERROR(chat->log, "Failed to delete peer %u", i);
+        }
+
+        if (i >= chat->numpeers) {
+            break;
         }
     }
 }

toxcore/group_common.h

@@ -133,6 +133,7 @@ typedef struct GC_Connection {
     bool        pending_key_rotation_request;
 
     bool        pending_delete;  /* true if this peer has been marked for deletion */
+    bool        delete_this_iteration;  /* true if this peer should be deleted this do_gc() iteration*/
     GC_Exit_Info exit_info;
 } GC_Connection;