Prevent task dependency calculation going into an infinite loop

new file mode 100644
index 0000000..690d116
@@ -0,0 +1,76 @@
+#! /usr/bin/env python
+# ex:ts=4:sw=4:sts=4:et
+# -*- tab-width: 4; c-basic-offset: 4; indent-tabs-mode: nil -*-
+#
+# BitBake Toaster Implementation
+#
+# Copyright (C) 2013-2016 Intel Corporation
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+from django.core.urlresolvers import reverse
+from django.utils import timezone
+from tests.browser.selenium_helpers import SeleniumTestCase
+from orm.models import Project, Build, Layer, Layer_Version, Recipe, Target
+from orm.models import Task, Task_Dependency
+
+class TestTaskPage(SeleniumTestCase):
+    """ Test page which shows an individual task """
+    RECIPE_NAME = 'bar'
+    RECIPE_VERSION = '0.1'
+    TASK_NAME = 'do_da_doo_ron_ron'
+
+    def setUp(self):
+        now = timezone.now()
+
+        project = Project.objects.get_or_create_default_project()
+
+        self.build = Build.objects.create(project=project, started_on=now,
+            completed_on=now)
+
+        Target.objects.create(target='foo', build=self.build)
+
+        layer = Layer.objects.create()
+
+        layer_version = Layer_Version.objects.create(layer=layer)
+
+        recipe = Recipe.objects.create(name=TestTaskPage.RECIPE_NAME,
+            layer_version=layer_version, version=TestTaskPage.RECIPE_VERSION)
+
+        self.task = Task.objects.create(build=self.build, recipe=recipe,
+            order=1, outcome=Task.OUTCOME_COVERED, task_executed=False,
+            task_name=TestTaskPage.TASK_NAME)
+
+    def test_covered_task(self):
+        """
+        Check that covered tasks are displayed for tasks which have
+        dependencies on themselves
+        """
+
+        # the infinite loop which of bug 9952 was down to tasks which
+        # depend on themselves, so add self-dependent tasks to replicate the
+        # situation which caused the infinite loop (now fixed)
+        Task_Dependency.objects.create(task=self.task, depends_on=self.task)
+
+        url = reverse('task', args=(self.build.id, self.task.id,))
+        self.get(url)
+
+        # check that we see the task name
+        self.wait_until_visible('.page-header h1')
+
+        heading = self.find('.page-header h1')
+        expected_heading = '%s_%s %s' % (TestTaskPage.RECIPE_NAME,
+            TestTaskPage.RECIPE_VERSION, TestTaskPage.TASK_NAME)
+        self.assertEqual(heading.text, expected_heading,
+            'Heading should show recipe name, version and task')

index a40ceef..3411806 100755
@@ -822,11 +822,21 @@ def _find_task_dep(task_object):
 def _find_task_revdep(task_object):
     tdeps = Task_Dependency.objects.filter(depends_on=task_object).filter(task__order__gt=0)
     tdeps = tdeps.exclude(task__outcome = Task.OUTCOME_NA).select_related("task", "task__recipe", "task__build")
+
+    # exclude self-dependencies to prevent infinite dependency loop
+    # in generateCoveredList2()
+    tdeps = tdeps.exclude(task=task_object)
+
     return [tdep.task for tdep in tdeps]
 
 def _find_task_revdep_list(tasklist):
     tdeps = Task_Dependency.objects.filter(depends_on__in=tasklist).filter(task__order__gt=0)
     tdeps = tdeps.exclude(task__outcome=Task.OUTCOME_NA).select_related("task", "task__recipe", "task__build")
+
+    # exclude self-dependencies to prevent infinite dependency loop
+    # in generateCoveredList2()
+    tdeps = tdeps.exclude(task=F('depends_on'))
+
     return [tdep.task for tdep in tdeps]
 
 def _find_task_provider(task_object):