cvetriager: modified access to remote branches of stable repos

Changed access to remote branches in order to for do_pull in common.py
to execute properly.

BUG=chromium:1093363
TEST=python setup.py test

Change-Id: I3c33229f8ab93c54eec4e347613009a793f09be3
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dev-util/+/2304696
Commit-Queue: Wanda Mora <morawand@chromium.org>
Tested-by: Wanda Mora <morawand@chromium.org>
Reviewed-by: Zubin Mithra <zsm@chromium.org>
diff --git a/contrib/cvetriager/cvelib/common.py b/contrib/cvetriager/cvelib/common.py
index 4a2d067..96277fb 100644
--- a/contrib/cvetriager/cvelib/common.py
+++ b/contrib/cvetriager/cvelib/common.py
@@ -13,10 +13,13 @@
     """Exception raised from common."""
 
 
-def get_stable_branch(kernel):
+def get_stable_branch(kernel, is_rc=False):
     """Returns stable branch name."""
     branch = kernel[1:]
-    return f'linux-{branch}.y'
+    remote = f'linux-{branch}.y'
+    if is_rc:
+        return kernel, remote
+    return remote, remote
 
 
 def get_cros_branch(kernel):
diff --git a/contrib/cvetriager/cvelib/contextgenerator.py b/contrib/cvetriager/cvelib/contextgenerator.py
index be57da6..c6293c2 100644
--- a/contrib/cvetriager/cvelib/contextgenerator.py
+++ b/contrib/cvetriager/cvelib/contextgenerator.py
@@ -83,21 +83,20 @@
 
         self.kernels = valid_kernels
 
-    def filter_based_on_stable(self, linux_sha, environment):
+    def filter_based_on_stable(self, linux_sha, env_var):
         """Filters out stable or stable-rc kernels with linux commit."""
         valid_kernels = []
+        environment = os.getenv(env_var)
+        is_rc = bool(env_var == 'STABLE_RC')
 
         subject = self.get_subject_line(linux_sha)
 
-        # Records whether the function is checking linux-stable or linux-stable-rc.
-        stable = os.path.basename(environment)
-
         for kernel in self.kernels:
-            self.logger.debug(f'Checking if {kernel} on {stable} contains {linux_sha}')
+            self.logger.debug(f'Checking if {kernel} on {env_var} contains {linux_sha}')
 
-            branch = common.get_stable_branch(kernel)
+            branch, remote = common.get_stable_branch(kernel, is_rc)
 
-            common.checkout_branch(kernel, branch, 'origin', branch, environment)
+            common.checkout_branch(kernel, branch, 'origin', remote, environment)
 
             if self.is_in_kernel(environment, subject, False):
                 valid_kernels.append(kernel)
@@ -166,9 +165,9 @@
 
         self.find_kernels_with_fixes_subj(linux_sha)
 
-        self.filter_based_on_stable(linux_sha, os.getenv('STABLE'))
+        self.filter_based_on_stable(linux_sha, 'STABLE')
 
-        self.filter_based_on_stable(linux_sha, os.getenv('STABLE_RC'))
+        self.filter_based_on_stable(linux_sha, 'STABLE_RC')
 
         if self.check_rel_commits:
             self.detect_relevant_commits(linux_sha)
diff --git a/contrib/cvetriager/tests/contextgenerator_test.py b/contrib/cvetriager/tests/contextgenerator_test.py
index 42cfbaa..9294998 100644
--- a/contrib/cvetriager/tests/contextgenerator_test.py
+++ b/contrib/cvetriager/tests/contextgenerator_test.py
@@ -79,9 +79,9 @@
         subprocess.check_call(['git', 'init'], stdout=subprocess.DEVNULL,
                               stderr=subprocess.DEVNULL, cwd=self.stable_rc_temp)
 
-        create_branch_and_commit_file(self.stable_rc_temp, 'linux-1.0.y', 'file', 'random subject')
+        create_branch_and_commit_file(self.stable_rc_temp, 'v1.0', 'file', 'random subject')
 
-        create_branch_and_commit_file(self.stable_rc_temp, 'linux-2.0.y', 'file2',
+        create_branch_and_commit_file(self.stable_rc_temp, 'v2.0', 'file2',
                                       TestContextGenerator.LINUX_SUBJECT)
 
     def tearDown(self):
@@ -171,13 +171,13 @@
         # Tests with $STABLE.
         cg = contextgenerator.ContextGenerator(['v1.0', 'v2.0'])
 
-        cg.filter_based_on_stable(TestContextGenerator.LINUX_SHA, os.getenv('STABLE'))
+        cg.filter_based_on_stable(TestContextGenerator.LINUX_SHA, 'STABLE')
 
         self.assertIn('v1.0', cg.kernels)
         self.assertNotIn('v2.0', cg.kernels)
 
         # Tests with $STABLE_RC.
-        cg.filter_based_on_stable(TestContextGenerator.LINUX_SHA, os.getenv('STABLE_RC'))
+        cg.filter_based_on_stable(TestContextGenerator.LINUX_SHA, 'STABLE_RC')
 
         self.assertIn('v1.0', cg.kernels)
         self.assertNotIn('v2.0', cg.kernels)