From 48147b7fd148a949268bd62db5297766d43406da Mon Sep 17 00:00:00 2001
From: yushijinhun <yushijinhun@gmail.com>
Date: Sun, 23 Jul 2017 16:53:42 +0800
Subject: [PATCH] Give up PGP decryption when intent is cancelled

When receiving a PGP message which is not encrypted with YOUR key,
OpenKeychain shows a dialog, which tells you the private key to decrypt
the message is unavailable. However, Conversations won't give up
decrypting the message. So whether the subsequent messages are
decryptable or not, the decryption is blocked at the current message.
The commit fixes the bug in this way: Give up the current message when
the decryption intent is cancelled, so that subsequent messages can be
handled.
---
 .../crypto/PgpDecryptionService.java          | 21 +++++++++++++++++++
 .../ui/ConversationFragment.java              |  5 +++++
 2 files changed, 26 insertions(+)

diff --git a/src/main/java/eu/siacs/conversations/crypto/PgpDecryptionService.java b/src/main/java/eu/siacs/conversations/crypto/PgpDecryptionService.java
index 53aa3e9f4..69bd5f70b 100644
--- a/src/main/java/eu/siacs/conversations/crypto/PgpDecryptionService.java
+++ b/src/main/java/eu/siacs/conversations/crypto/PgpDecryptionService.java
@@ -69,6 +69,27 @@ public class PgpDecryptionService {
         this.pendingNotifications.remove(message);
     }
 
+    public void giveUpCurrentDecryption(){
+        Message message;
+        synchronized (this) {
+            if(currentMessage != null) {
+                return;
+            }
+            message = messages.peekFirst();
+            if (message == null) {
+                return;
+            }
+            discard(message);
+        }
+        synchronized (message){
+            if (message.getEncryption() == Message.ENCRYPTION_PGP) {
+                message.setEncryption(Message.ENCRYPTION_DECRYPTION_FAILED);
+            }
+        }
+        mXmppConnectionService.updateMessage(message);
+        continueDecryption(true);
+    }
+
 	protected synchronized void decryptNext() {
 		if (pendingIntent == null
                 && getOpenPgpApi() != null
diff --git a/src/main/java/eu/siacs/conversations/ui/ConversationFragment.java b/src/main/java/eu/siacs/conversations/ui/ConversationFragment.java
index afdabcfe8..635a96274 100644
--- a/src/main/java/eu/siacs/conversations/ui/ConversationFragment.java
+++ b/src/main/java/eu/siacs/conversations/ui/ConversationFragment.java
@@ -1658,6 +1658,11 @@ public class ConversationFragment extends Fragment implements EditMessage.Keyboa
 				int choice = data.getIntExtra("choice", ConversationActivity.ATTACHMENT_CHOICE_INVALID);
 				activity.selectPresenceToAttachFile(choice, conversation.getNextEncryption());
 			}
+		} else if (resultCode == Activity.RESULT_CANCELED) {
+			if (requestCode == ConversationActivity.REQUEST_DECRYPT_PGP) {
+				// discard the message to prevent decryption being blocked
+				conversation.getAccount().getPgpDecryptionService().giveUpCurrentDecryption();
+			}
 		}
 	}