[FIX] web: do not crash when saving if offline

Be in a form view, edit some fields, simulate a connection lost
(e.g. with devtools network throttling). Leave the form, e.g. by
clicking on the breadcrumb. Before this commit, there was a crash,
because the web_save returned a ConnectionLostError and that error
wasn't properly handled. With this commit, we remain in the form,
and if the connection is back later on, the user is able to leave
and save again.

part of task~5106517

closes odoo#229492

Related: odoo/enterprise#96626
Signed-off-by: Aaron Bohy (aab) <aab@odoo.com>

Author: aab-odoo

addons/web/static/src/views/form/form_controller.js

@@ -45,6 +45,7 @@ import {
 } from "@odoo/owl";
 import { FetchRecordError } from "@web/model/relational_model/errors";
 import { effect } from "@web/core/utils/reactive";
+import { ConnectionLostError } from "@web/core/network/rpc";
 
 const viewRegistry = registry.category("views");
 
@@ -427,6 +428,9 @@ export class FormController extends Component {
     async onWillSaveRecord() {}
 
     async onSaveError(error, { discard, retry }, leaving) {
+        if (error instanceof ConnectionLostError) {
+            return false;
+        }
         const suggestedCompany = error.data?.context?.suggested_company;
         const activeCompanyIds = user.activeCompanies.map((c) => c.id);
         if (

addons/web/static/tests/views/form/form_view.test.js

@@ -298,6 +298,119 @@ test(`[Offline] form switches to readonly in offline mode`, async () => {
     expect(`.o_field_x2many_list_row_add`).toHaveCount(1);
 });
 
+test(`[Offline] save a form view offline (click save icon)`, async () => {
+    let offline = false;
+    onRpc(
+        "/web/dataset/call_kw/partner/web_save",
+        () => {
+            expect.step("web_save");
+            if (offline) {
+                return new Response("", { status: 502 });
+            }
+        },
+        { pure: true }
+    );
+
+    Partner._views = {
+        form: `<form><field name="foo"/></form>`,
+        list: `<list><field name="foo"/></list>`,
+        search: `<search/>`,
+    };
+    defineActions([
+        {
+            id: 1,
+            name: "Partner",
+            res_model: "partner",
+            views: [
+                [false, "list"],
+                [false, "form"],
+            ],
+        },
+    ]);
+
+    await mountWithCleanup(WebClient);
+    await getService("action").doAction(1);
+
+    await contains(".o_data_row .o_data_cell").click();
+    expect(".o_form_renderer").toHaveClass("o_form_editable");
+    expect(".o_field_widget[name=foo] input").toHaveValue("yop");
+    await contains(".o_field_widget[name=foo] input").edit("new foo");
+
+    offline = true;
+    await contains(".o_form_button_save").click();
+    expect(".o_form_renderer").toHaveClass("o_form_readonly");
+    expect(".o_field_widget[name=foo]").toHaveText("new foo");
+    expect(getService("offline").status.offline).toBe(true);
+    expect.verifySteps(["web_save"]);
+
+    offline = false;
+    getService("offline").status.offline = false;
+    await animationFrame();
+    expect(".o_form_renderer").toHaveClass("o_form_editable");
+    await contains(".o_form_button_save").click();
+    expect.verifySteps(["web_save"]);
+
+    await contains(".o_breadcrumb .o_back_button").click();
+    expect(".o_data_cell:first").toHaveText("new foo");
+});
+
+test(`[Offline] save a form view offline (autosave when leaving)`, async () => {
+    // this test is the same as above, but in this one we don't manually save
+    // the record before leaving
+    let offline = false;
+    onRpc(
+        "/web/dataset/call_kw/partner/web_save",
+        () => {
+            expect.step("web_save");
+            if (offline) {
+                return new Response("", { status: 502 });
+            }
+        },
+        { pure: true }
+    );
+
+    Partner._views = {
+        form: `<form><field name="foo"/></form>`,
+        list: `<list><field name="foo"/></list>`,
+        search: `<search/>`,
+    };
+    defineActions([
+        {
+            id: 1,
+            name: "Partner",
+            res_model: "partner",
+            views: [
+                [false, "list"],
+                [false, "form"],
+            ],
+        },
+    ]);
+
+    await mountWithCleanup(WebClient);
+    await getService("action").doAction(1);
+
+    await contains(".o_data_row .o_data_cell").click();
+    expect(".o_form_renderer").toHaveClass("o_form_editable");
+    expect(".o_field_widget[name=foo] input").toHaveValue("yop");
+    await contains(".o_field_widget[name=foo] input").edit("new foo");
+
+    offline = true;
+    await contains(".o_breadcrumb .o_back_button").click();
+    expect(".o_form_renderer").toHaveClass("o_form_readonly");
+    expect(".o_field_widget[name=foo]").toHaveText("new foo");
+    expect(getService("offline").status.offline).toBe(true);
+    expect.verifySteps(["web_save"]);
+
+    offline = false;
+    getService("offline").status.offline = false;
+    await animationFrame();
+    expect(".o_form_renderer").toHaveClass("o_form_editable");
+
+    await contains(".o_breadcrumb .o_back_button").click();
+    expect(".o_data_cell:first").toHaveText("new foo");
+    expect.verifySteps(["web_save"]);
+});
+
 test(`form rendering with class and style attributes`, async () => {
     await mountView({
         resModel: "partner",