Merge "Document Signature equals/hash should not include flags" into sc-dev (969c4968) · Commits · e / os / android_frameworks_base

core/java/android/content/pm/Signature.java

+4 −0

Original line number	Diff line number	Diff line
		@@ -256,6 +256,8 @@ public class Signature implements Parcelable {
		try {
		if (obj != null) {
		Signature other = (Signature)obj;
		// Note, some classes, such as PackageParser.SigningDetails, rely on equals
		// only comparing the mSignature arrays without the flags.
		return this == other \|\| Arrays.equals(mSignature, other.mSignature);
		}
		} catch (ClassCastException e) {
		@@ -268,6 +270,8 @@ public class Signature implements Parcelable {
		if (mHaveHashCode) {
		return mHashCode;
		}
		// Note, similar to equals some classes rely on the hash code not including
		// the flags for Set membership checks.
		mHashCode = Arrays.hashCode(mSignature);
		mHaveHashCode = true;
		return mHashCode;

core/tests/coretests/src/android/content/pm/SignatureTest.java

+26 −0

Original line number	Diff line number	Diff line
		@@ -54,6 +54,32 @@ public class SignatureTest extends TestCase {
		assertFalse(Signature.areEffectiveMatch(asArray(A, M), asArray(A, B)));
		}

		public void testHashCode_doesNotIncludeFlags() throws Exception {
		// Some classes rely on the hash code not including the flags / capabilities for the signer
		// to verify Set membership. This test verifies two signers with the same signature but
		// different flags have the same hash code.
		Signature signatureAWithAllCaps = new Signature(A.toCharsString());
		// There are currently 5 capabilities that can be assigned to a previous signer, although
		// for the purposes of this test all that matters is that the two flag values are distinct.
		signatureAWithAllCaps.setFlags(31);
		Signature signatureAWithNoCaps = new Signature(A.toCharsString());
		signatureAWithNoCaps.setFlags(0);

		assertEquals(signatureAWithAllCaps.hashCode(), signatureAWithNoCaps.hashCode());
		}

		public void testEquals_doesNotIncludeFlags() throws Exception {
		// Similar to above some classes rely on equals only comparing the signature arrays
		// for equality without including the flags. This test verifies two signers with the
		// same signature but different flags are still considered equal.
		Signature signatureAWithAllCaps = new Signature(A.toCharsString());
		signatureAWithAllCaps.setFlags(31);
		Signature signatureAWithNoCaps = new Signature(A.toCharsString());
		signatureAWithNoCaps.setFlags(0);

		assertEquals(signatureAWithAllCaps, signatureAWithNoCaps);
		}

		private static Signature[] asArray(Signature... s) {
		return s;
		}