prevented passphrase caching on revocation

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/operations/EditKeyOperation.java

@@ -161,7 +161,7 @@ public class EditKeyOperation extends BaseOperation<SaveKeyringParcel> {
         }
 
         // There is a new passphrase - cache it
-        if (saveParcel.mNewUnlock != null) {
+        if (saveParcel.mNewUnlock != null && cryptoInput.mCachePassphrase) {
             log.add(LogType.MSG_ED_CACHING_NEW, 1);
 
             // NOTE: Don't cache empty passphrases! Important for MOVE_KEY_TO_CARD

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/operations/RevokeOperation.java

@@ -32,6 +32,9 @@ public class RevokeOperation extends  BaseOperation<RevokeKeyringParcel> {
     public OperationResult execute(RevokeKeyringParcel revokeKeyringParcel,
                                    CryptoInputParcel cryptoInputParcel) {
 
+        // we don't cache passphrases during revocation
+        cryptoInputParcel.mCachePassphrase = false;
+
         long masterKeyId = revokeKeyringParcel.mMasterKeyId;
 
         OperationResult.OperationLog log = new OperationResult.OperationLog();