fix: guard .first() queries against None to prevent AttributeError

Three queries called .first().value or .first().commit without
checking for None. On a fresh install or empty database, these
crash with AttributeError.

Fixed in mod_ci/controllers.py, mod_home/controllers.py, and
mod_sample/controllers.py.

Author: Dhanush Varma

mod_ci/controllers.py

@@ -993,8 +993,18 @@ def start_test(compute, app, db, repository: Repository.Repository, test, bot_to
 
     categories = Category.query.order_by(Category.id.desc()).all()
     commit_name = 'fetch_commit_' + test.platform.value
-    commit_hash = GeneralData.query.filter(GeneralData.key == commit_name).first().value
-    last_commit = Test.query.filter(and_(Test.commit == commit_hash, Test.platform == test.platform)).first()
+    commit_entry = GeneralData.query.filter(GeneralData.key == commit_name).first()
+    if commit_entry is None:
+        log.warning(f'No commit hash found for {commit_name}, skipping comparison')
+        commit_hash = None
+    else:
+        commit_hash = commit_entry.value
+    last_commit = (
+        Test.query.filter(
+            and_(Test.commit == commit_hash,
+                 Test.platform == test.platform)
+        ).first() if commit_hash else None
+    )
 
     if last_commit is not None:
         log.debug(f"[{gcp_instance_name}] We will compare against the results of test {last_commit.id}")
@@ -1031,7 +1041,7 @@ def start_test(compute, app, db, repository: Repository.Repository, test, bot_to
             output_node.text = regression_test.output_type.value
             compare = etree.SubElement(entry, 'compare')
             last_files = TestResultFile.query.filter(and_(
-                TestResultFile.test_id == last_commit.id,
+                TestResultFile.test_id == last_commit.id,  # type: ignore
                 TestResultFile.regression_test_id == regression_test.id
             )).subquery()
 

mod_home/controllers.py

@@ -22,7 +22,8 @@ def before_app_request() -> None:
 @template_renderer()
 def index():
     """Render index home page."""
-    last_commit = GeneralData.query.filter(GeneralData.key == 'last_commit').first().value
+    last_commit_entry = GeneralData.query.filter(GeneralData.key == 'last_commit').first()
+    last_commit = last_commit_entry.value if last_commit_entry is not None else None
     last_release = CCExtractorVersion.query.order_by(CCExtractorVersion.released.desc()).first()
     test_access = False
     if g.user is not None and g.user.role in [Role.tester, Role.contributor, Role.admin]:

mod_sample/controllers.py

@@ -56,11 +56,13 @@ def display_sample_info(sample) -> Dict[str, Any]:
             # in case no media info present in the sample
             media_info = None
 
-    latest_commit = GeneralData.query.filter(GeneralData.key == 'last_commit').first().value
-    last_release = CCExtractorVersion.query.order_by(CCExtractorVersion.released.desc()).first().commit
+    latest_commit_entry = GeneralData.query.filter(GeneralData.key == 'last_commit').first()
+    latest_commit = latest_commit_entry.value if latest_commit_entry is not None else None
+    last_release_entry = CCExtractorVersion.query.order_by(CCExtractorVersion.released.desc()).first()
+    last_release = last_release_entry.commit if last_release_entry is not None else None
 
-    test_commit = Test.query.filter(Test.commit == latest_commit).first()
-    test_release = Test.query.filter(Test.commit == last_release).first()
+    test_commit = Test.query.filter(Test.commit == latest_commit).first() if latest_commit else None
+    test_release = Test.query.filter(Test.commit == last_release).first() if last_release else None
     regression_tests = RegressionTest.query.filter(RegressionTest.sample_id == sample.id).all()
     status = 'Unknown'
     status_release = 'Unknown'

templates/sample/index.html

@@ -9,6 +9,8 @@
             <div class="column medium-8">
                 <h1>Sample information</h1>
                 <p>Please select one of the samples below to see more detailed information about it.</p>
+                {% set use_sample_original=true %}
+                {% set use_sample_original=true %}
                 {% include "sample/list_samples.html" %}
             </div>
         </div>