Keep a filter written before the dialog's back() lands

src/common/navigate.ts

@@ -1,4 +1,7 @@
-import { closeAllDialogs } from "../dialogs/make-dialog-manager";
+import {
+  closeAllDialogs,
+  updateClosedDialogSearch,
+} from "../dialogs/make-dialog-manager";
 import { fireEvent } from "./dom/fire_event";
 import { mainWindow } from "./dom/get_main_window";
 import { currentPath } from "./url/current-path";
@@ -42,6 +45,7 @@ export const updateHistoryState = (patch: Record<string, unknown>) => {
  */
 export const replaceCurrentUrl = (url: string) => {
   mainWindow.history.replaceState(mainWindow.history.state, "", url);
+  updateClosedDialogSearch();
   rememberCurrentEntry();
 };
 

src/dialogs/make-dialog-manager.ts

@@ -65,6 +65,9 @@ const LOADED: LoadedDialogsDict = {};
 const OPEN_DIALOG_STACK: DialogState[] = [];
 export const FOCUS_TARGET = Symbol.for("HA focus target");
 
+/** The URL of the last dialog's entry, when the dialog went back to close. */
+let closedDialogUrl: { pathname: string; search: string } | undefined;
+
 /**
  * Shows a dialog element, lazy-loading it if needed, and optionally integrates
  * dialog open/close behavior with browser history.
@@ -240,6 +243,41 @@ export const closeLastDialog = async (historyState?: any) => {
   return true;
 };
 
+/**
+ * Called on the back() of a dialog that closed itself. The page's entry still
+ * has the URL from before the dialog opened, so a change to the search made
+ * while it was open, like a filter written after a delete, is kept. Must run
+ * before anything else reads the URL on that popstate.
+ */
+export const restoreClosedDialogSearch = () => {
+  const closedUrl = closedDialogUrl;
+  closedDialogUrl = undefined;
+  const { history, location } = mainWindow;
+
+  if (
+    closedUrl?.pathname === location.pathname &&
+    closedUrl.search !== location.search
+  ) {
+    history.replaceState(
+      history.state,
+      "",
+      `${location.pathname}${closedUrl.search}${location.hash}`
+    );
+  }
+};
+
+/**
+ * Called after the current entry's URL is rewritten. Until the back() of a
+ * closed dialog lands, that is still the dialog's entry, so keep its search
+ * for restoreClosedDialogSearch().
+ */
+export const updateClosedDialogSearch = () => {
+  if (closedDialogUrl) {
+    const { pathname, search } = mainWindow.location;
+    closedDialogUrl = { pathname, search };
+  }
+};
+
 export const closeAllDialogs = async () => {
   for (let i = OPEN_DIALOG_STACK.length - 1; i >= 0; i--) {
     const closed =
@@ -270,6 +308,8 @@ const _handleClosed = (ev: HASSDomEvent<DialogClosedParams>) => {
       );
     } else if (dialogIndex !== -1) {
       // if the dialog is the last one and it was indeed open, go back
+      const { pathname, search } = mainWindow.location;
+      closedDialogUrl = { pathname, search };
       mainWindow.history.back();
     }
   }

src/state/url-sync-mixin.ts

@@ -3,7 +3,10 @@ import type { ReactiveElement, PropertyValues } from "lit";
 import { fireEvent } from "../common/dom/fire_event";
 import { mainWindow } from "../common/dom/get_main_window";
 import { updateHistoryState } from "../common/navigate";
-import { closeLastDialog } from "../dialogs/make-dialog-manager";
+import {
+  closeLastDialog,
+  restoreClosedDialogSearch,
+} from "../dialogs/make-dialog-manager";
 import type { ProvideHassElement } from "../mixins/provide-hass-lit-mixin";
 import type { Constructor } from "../types";
 
@@ -64,6 +67,9 @@ export const urlSyncMixin = <
               console.log("popstate", ev);
             }
             if (ev.state.opensDialog) {
+              // This listener is added before any page's, so pages read the
+              // restored URL
+              restoreClosedDialogSearch();
               // coming back from a dialog
               // if we are instead navigating forward, the dialogs are already closed
               closeLastDialog();