[FIX] web: deadlines are not visible in day/week calendar views

Due to commit odoo/odoo@0150141756
when the widget calendar is initialized with date type record for
date_start and without all_day mapping events aren't shown on day/week
views. This is because all day zone isn't visible when all_day mapping
is not set.

After this commit, we show the all day zone also when the date_start is
a date type.

Steps to reproduce:
* Go to Project App
* Select/Create a project
* Select/Add a task with a deadline
* Return to project
* Select calendar view
* Select week view (of the deadline) => BUG

closes odoo/odoo#51818

X-original-commit: 1d83f4184e1b82db4dd4db54d98e509432340996
Signed-off-by: Adrien Dieudonné (adr) <adr@odoo.com>
Signed-off-by: rfr-odoo <rfr-odoo@users.noreply.github.com>

addons/web/static/src/js/views/calendar/calendar_model.js

@@ -452,7 +452,7 @@ return AbstractModel.extend({
             dayNamesShort: moment.weekdaysShort(),
             firstDay: this.week_start,
             slotLabelFormat: _t.database.parameters.time_format.search("%H") !== -1 ? format24Hour : format12Hour,
-            allDaySlot: this.mapping.all_day,
+            allDaySlot: this.mapping.all_day || this.fields[this.mapping.date_start].type === 'date',
         };
     },
     /**

addons/web/static/tests/views/calendar_tests.js

@@ -2468,6 +2468,26 @@ QUnit.module('Views', {
         calendar.destroy();
     });
 
+    QUnit.test('set event as all day when field is date (without all_day mapping)', async function (assert) {
+        assert.expect(1);
+
+        this.data.event.records[0].start_date = "2016-12-14";
+
+        var calendar = await createCalendarView({
+            View: CalendarView,
+            model: 'event',
+            data: this.data,
+            arch: `<calendar date_start="start_date" mode="week"></calendar>`,
+            archs: archs,
+            viewOptions: {
+                initialDate: initialDate,
+            },
+        });
+        assert.containsOnce(calendar, '.fc-day-grid .fc-event-container',
+            "should be one event in the all day row");
+        calendar.destroy();
+    });
+
     QUnit.test('quickcreate avoid double event creation', async function (assert) {
         assert.expect(1);
         var createCount = 0;