[FIX] web: multi lines don't work in warnings

Steps to reproduce:

1- install sales
2- allow warnings on sale orders
3- set a warning w with multiple lines on
 sale order on customer c
4- try to add c to a sale order
5- w will be shown in one line

Bug:

the html is escaped and the proper styling is missing

Fix:
add the proper style

OPW-2847660

closes odoo/odoo#94730

X-original-commit: 36546f39ca44f6d5691e3b1d8a7d1eb2da4a7b51
Signed-off-by: Aaron Bohy (aab) <aab@odoo.com>
Signed-off-by: Mohamed Megahed Abbas Megahed SALLAM (mome) <mome@odoo.com>

addons/web/static/src/legacy/action_adapters.js

@@ -26,7 +26,7 @@ const {
 
 class WarningDialog extends Component {}
 WarningDialog.template = xml`<Dialog title="props.title">
-    <t t-esc="props.message"/>
+    <p style="white-space:pre-wrap" t-esc="props.message"/>
 </Dialog>`;
 WarningDialog.components = { Dialog };
 

addons/web/static/tests/webclient/actions/legacy_tests.js

@@ -91,6 +91,32 @@ QUnit.module("ActionManager", (hooks) => {
         assert.strictEqual($(".modal-body").text(), "This is a warning...");
     });
 
+    QUnit.test("display multiline warning as modal", async function (assert) {
+        assert.expect(5);
+        let list;
+        patchWithCleanup(ListController.prototype, {
+            init() {
+                this._super(...arguments);
+                list = this;
+            },
+        });
+
+        const webClient = await createWebClient({ serverData });
+        await doAction(webClient, 3);
+        assert.containsOnce(target, ".o_list_view");
+        list.trigger_up("warning", {
+            title: "Warning!!!",
+            message: "This is a warning...\nabc",
+            type: "dialog",
+        });
+        await testUtils.nextTick();
+        await legacyExtraNextTick();
+        assert.containsOnce(target, ".o_list_view");
+        assert.containsOnce(document.body, ".modal");
+        assert.strictEqual($(".modal-title").text(), "Warning!!!");
+        assert.strictEqual($(".modal-body")[0].innerText, "This is a warning...\nabc");
+    });
+
     QUnit.test(
         "legacy crash manager is still properly remapped to error service",
         async function (assert) {