Merge Simon Arlott's 'bug-777472' into stable.

gnucash/gnome/gnc-plugin-page-account-tree.c

@@ -1782,6 +1782,17 @@ gnc_plugin_page_account_tree_cmd_reconcile (GSimpleAction *simple,
     account = gnc_plugin_page_account_tree_get_current_account (page);
     g_return_if_fail (account != NULL);
 
+    /* To prevent mistakes involving saving an edited transaction after
+     * finishing a reconciliation (reverting the reconcile state), we could look
+     * at all open registers and determine if any of them have a transaction
+     * being edited that involves the account to be reconciled.
+     *
+     * However, the reconcile window isn't modal so it's still possible to start
+     * editing a transaction after opening it. Assume the user knows what
+     * they're doing if they start a reconciliation from the account tree and
+     * don't attempt to stop them.
+     */
+
     window = GNC_PLUGIN_PAGE (page)->window;
     recnData = recnWindow (window, account);
     gnc_ui_reconcile_window_raise (recnData);

gnucash/gnome/gnc-plugin-page-register.c

@@ -4327,6 +4327,17 @@ gnc_plugin_page_register_cmd_reconcile (GSimpleAction *simple,
 
     g_return_if_fail (GNC_IS_PLUGIN_PAGE_REGISTER (page));
 
+    /* To prevent mistakes involving saving an edited transaction after
+     * finishing a reconciliation (reverting the reconcile state), require
+     * pending activity on the current register to be finished.
+     *
+     * The reconcile window isn't modal so it's still possible to start editing
+     * a transaction after opening it, but at that point the user should know
+     * what they're doing is unsafe.
+     */
+    if (!gnc_plugin_page_register_finish_pending (GNC_PLUGIN_PAGE (page)))
+        return;
+
     account = gnc_plugin_page_register_get_account (page);
 
     window = gnc_window_get_gtk_window (GNC_WINDOW (GNC_PLUGIN_PAGE (