[FIX] runbot: ensure that commit date is always set

When exporting a commit, the commit date is used in the `tar` command to
set the date of the exported folder. On the other hand it happens that a
commit is not found in the database and should be quickly created on the
fly. e.g.: with the `_get` method. In this case, if the commit needs to
be exported later, the method fails and may break a runbot build.

It happened with a custom python step.

runbot/models/commit.py

@@ -34,6 +34,13 @@ class Commit(models.Model):
     dname = fields.Char('Display name', compute='_compute_dname')
     rebase_on_id = fields.Many2one('runbot.commit', 'Rebase on commit')
 
+    @api.model_create_multi
+    def create(self, vals_list):
+        for vals in vals_list:
+            if 'date' not in vals:
+                vals['date'] = fields.Datetime.now()
+        return super().create(vals_list)
+
     def _get(self, name, repo_id, vals=None, rebase_on_id=False):
         commit = self.search([('name', '=', name), ('repo_id', '=', repo_id), ('rebase_on_id', '=', rebase_on_id)])
         if not commit:

runbot/tests/test_commit.py

@@ -6,6 +6,17 @@ from werkzeug.urls import url_parse
 from odoo.tests.common import HttpCase, new_test_user, tagged
 from odoo.tools import mute_logger
 
+from .common import RunbotCaseMinimalSetup
+
+class TestCommitDate(RunbotCaseMinimalSetup):
+
+    def test_commit_has_date(self):
+        commit = self.Commit.create({
+            'name': 'caca00caca00ffffffffffffffffffffffffffff',
+            'repo_id': self.repo_server.id
+        })
+
+        self.assertNotEqual(commit.date, False, "A commit should always have a date")
 
 @tagged('post_install', '-at_install')
 class TestCommitStatus(HttpCase):