releasetools: Remove the name restriction in common.GetSparseImage.

The function used to be serving system and vendor partitions only (as
they were the only partitions using sparse image at the point). The code
itself doesn't rely on anything specific to system/vendor.

Test: python -m unittest test_common
Change-Id: Ia4ecdeedb262f3d9db082128eaf9bab299983333

tools/releasetools/common.py

@@ -834,7 +834,7 @@ def GetSparseImage(which, tmpdir, input_zip, allow_shared_blocks,
   reconstructed from the block list, for whom we should avoid applying imgdiff.
 
   Args:
-    which: The partition name, which must be "system" or "vendor".
+    which: The partition name, e.g. "system", "vendor".
     tmpdir: The directory that contains the prebuilt image and block map file.
     input_zip: The target-files ZIP archive.
     allow_shared_blocks: Whether having shared blocks is allowed.
@@ -843,8 +843,6 @@ def GetSparseImage(which, tmpdir, input_zip, allow_shared_blocks,
   Returns:
     A SparseImage object, with file_map info loaded.
   """
-  assert which in ("system", "vendor")
-
   path = os.path.join(tmpdir, "IMAGES", which + ".img")
   mappath = os.path.join(tmpdir, "IMAGES", which + ".map")
 

tools/releasetools/test_common.py

@@ -641,11 +641,13 @@ class CommonUtilsTest(test_utils.ReleaseToolsTestCase):
         },
         sparse_image.file_map)
 
-  def test_GetSparseImage_invalidImageName(self):
+  def test_GetSparseImage_missingImageFile(self):
     self.assertRaises(
-        AssertionError, common.GetSparseImage, 'system2', None, None, False)
+        AssertionError, common.GetSparseImage, 'system2', self.testdata_dir,
+        None, False)
     self.assertRaises(
-        AssertionError, common.GetSparseImage, 'unknown', None, None, False)
+        AssertionError, common.GetSparseImage, 'unknown', self.testdata_dir,
+        None, False)
 
   def test_GetSparseImage_missingBlockMapFile(self):
     target_files = common.MakeTempFile(prefix='target_files-', suffix='.zip')