fix ninjalog_uploader.py

This is to fix https://crbug.com/1288639#c5

Bug: 1288639
Change-Id: Ife224fb5d5fe4faa4a78785828d4fa488fda3c6e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/3403475
Commit-Queue: Takuto Ikuta <tikuta@chromium.org>
Auto-Submit: Takuto Ikuta <tikuta@chromium.org>
Reviewed-by: Fumitoshi Ukai <ukai@google.com>
Commit-Queue: Fumitoshi Ukai <ukai@google.com>

ninjalog_uploader.py

@@ -45,7 +45,10 @@ def IsGoogler():
                      shell=True)
   if p.returncode != 0:
     return False
-  l = p.stdout.splitlines()[0]
+  lines = p.stdout.splitlines()
+  if len(lines) == 0:
+    return False
+  l = lines[0]
   # |l| will be like 'Login as <user>@google.com' for googler using goma.
   return l.startswith('Login as ') and l.endswith('@google.com')
 

tests/ninjalog_uploader_test.py

@@ -25,7 +25,11 @@ class NinjalogUploaderTest(unittest.TestCase):
 
     with unittest.mock.patch('subprocess.run') as run_mock:
       run_mock.return_value.returncode = 1
-      run_mock.return_value.stdout = 'Not logged in\n'
+      self.assertFalse(ninjalog_uploader.IsGoogler())
+
+    with unittest.mock.patch('subprocess.run') as run_mock:
+      run_mock.return_value.returncode = 0
+      run_mock.return_value.stdout = ''
       self.assertFalse(ninjalog_uploader.IsGoogler())
 
     with unittest.mock.patch('subprocess.run') as run_mock: