return InvalidJid object instead of null if Jid can not be parsed

12 files changed, 232 insertions, 51 deletions

diff --git a/src/main/java/de/pixart/messenger/entities/Bookmark.java b/src/main/java/de/pixart/messenger/entities/Bookmark.java
index 309c08e0f..079b283c0 100644
--- a/src/main/java/de/pixart/messenger/entities/Bookmark.java
+++ b/src/main/java/de/pixart/messenger/entities/Bookmark.java
@@ -11,6 +11,7 @@ import java.util.Locale;
 
 import de.pixart.messenger.utils.UIHelper;
 import de.pixart.messenger.xml.Element;
+import de.pixart.messenger.xmpp.InvalidJid;
 import rocks.xmpp.addr.Jid;
 
 public class Bookmark extends Element implements ListItem {
@@ -35,7 +36,7 @@ public class Bookmark extends Element implements ListItem {
         Bookmark bookmark = new Bookmark(account);
         bookmark.setAttributes(element.getAttributes());
         bookmark.setChildren(element.getChildren());
-        bookmark.jid =  bookmark.getAttributeAsJid("jid");
+        bookmark.jid = InvalidJid.getNullForInvalid(bookmark.getAttributeAsJid("jid"));
         return bookmark;
     }
 
diff --git a/src/main/java/de/pixart/messenger/parser/AbstractParser.java b/src/main/java/de/pixart/messenger/parser/AbstractParser.java
index 50204cb7b..e0a26c18d 100644
--- a/src/main/java/de/pixart/messenger/parser/AbstractParser.java
+++ b/src/main/java/de/pixart/messenger/parser/AbstractParser.java
@@ -10,6 +10,7 @@ import de.pixart.messenger.entities.Conversation;
 import de.pixart.messenger.entities.MucOptions;
 import de.pixart.messenger.services.XmppConnectionService;
 import de.pixart.messenger.xml.Element;
+import de.pixart.messenger.xmpp.InvalidJid;
 import de.pixart.messenger.xmpp.stanzas.AbstractStanza;
 import rocks.xmpp.addr.Jid;
 
@@ -36,7 +37,7 @@ public abstract class AbstractParser {
         }
         for (Element child : element.getChildren()) {
             if ("delay".equals(child.getName()) && "urn:xmpp:delay".equals(child.getNamespace())) {
-                final Jid f = to == null ? null : child.getAttributeAsJid("from");
+                final Jid f = to == null ? null : InvalidJid.getNullForInvalid(child.getAttributeAsJid("from"));
                 if (f != null && (to.asBareJid().equals(f) || to.getDomain().equals(f.toString()))) {
                     continue;
                 }
@@ -114,7 +115,9 @@ public abstract class AbstractParser {
         }
         Jid realJid = item.getAttributeAsJid("jid");
         MucOptions.User user = new MucOptions.User(conference.getMucOptions(), fullJid);
-        user.setRealJid(realJid);
+        if (InvalidJid.isValid(realJid)) {
+            user.setRealJid(realJid);
+        }
         user.setAffiliation(affiliation);
         user.setRole(role);
         return user;
diff --git a/src/main/java/de/pixart/messenger/parser/IqParser.java b/src/main/java/de/pixart/messenger/parser/IqParser.java
index 8f8cf9ae4..04ce4afaa 100644
--- a/src/main/java/de/pixart/messenger/parser/IqParser.java
+++ b/src/main/java/de/pixart/messenger/parser/IqParser.java
@@ -29,6 +29,7 @@ import de.pixart.messenger.entities.Contact;
 import de.pixart.messenger.services.XmppConnectionService;
 import de.pixart.messenger.utils.Namespace;
 import de.pixart.messenger.xml.Element;
+import de.pixart.messenger.xmpp.InvalidJid;
 import de.pixart.messenger.xmpp.OnIqPacketReceived;
 import de.pixart.messenger.xmpp.OnUpdateBlocklist;
 import de.pixart.messenger.xmpp.stanzas.IqPacket;
@@ -47,7 +48,7 @@ public class IqParser extends AbstractParser implements OnIqPacketReceived {
         }
         for (final Element item : query.getChildren()) {
             if (item.getName().equals("item")) {
-                final Jid jid = item.getAttributeAsJid("jid");
+                final Jid jid = InvalidJid.getNullForInvalid(item.getAttributeAsJid("jid"));
                 if (jid == null) {
                     continue;
                 }
@@ -310,7 +311,7 @@ public class IqParser extends AbstractParser implements OnIqPacketReceived {
                 // Create a collection of Jids from the packet
                 for (final Element item : items) {
                     if (item.getName().equals("item")) {
-                        final Jid jid = item.getAttributeAsJid("jid");
+                        final Jid jid = InvalidJid.getNullForInvalid(item.getAttributeAsJid("jid"));
                         if (jid != null) {
                             jids.add(jid);
                         }
@@ -344,7 +345,7 @@ public class IqParser extends AbstractParser implements OnIqPacketReceived {
                 final Collection<Jid> jids = new ArrayList<>(items.size());
                 for (final Element item : items) {
                     if (item.getName().equals("item")) {
-                        final Jid jid = item.getAttributeAsJid("jid");
+                        final Jid jid = InvalidJid.getNullForInvalid(item.getAttributeAsJid("jid"));
                         if (jid != null) {
                             jids.add(jid);
                         }
diff --git a/src/main/java/de/pixart/messenger/parser/MessageParser.java b/src/main/java/de/pixart/messenger/parser/MessageParser.java
index 1f3166015..5e307531f 100644
--- a/src/main/java/de/pixart/messenger/parser/MessageParser.java
+++ b/src/main/java/de/pixart/messenger/parser/MessageParser.java
@@ -40,6 +40,7 @@ import de.pixart.messenger.services.XmppConnectionService;
 import de.pixart.messenger.utils.CryptoHelper;
 import de.pixart.messenger.utils.Namespace;
 import de.pixart.messenger.xml.Element;
+import de.pixart.messenger.xmpp.InvalidJid;
 import de.pixart.messenger.xmpp.OnMessagePacketReceived;
 import de.pixart.messenger.xmpp.chatstate.ChatState;
 import de.pixart.messenger.xmpp.pep.Avatar;
@@ -73,7 +74,7 @@ public class MessageParser extends AbstractParser implements OnMessagePacketRece
         for (Element child : packet.getChildren()) {
             if (child.getName().equals("stanza-id")
                     && Namespace.STANZA_IDS.equals(child.getNamespace())
-                    && by.equals(child.getAttributeAsJid("by"))) {
+                    && by.equals(InvalidJid.getNullForInvalid(child.getAttributeAsJid("by")))) {
                 return child.getAttribute("id");
             }
         }
@@ -82,7 +83,7 @@ public class MessageParser extends AbstractParser implements OnMessagePacketRece
 
     private static Jid getTrueCounterpart(Element mucUserElement, Jid fallback) {
         final Element item = mucUserElement == null ? null : mucUserElement.findChild("item");
-        Jid result = item == null ? null : item.getAttributeAsJid("jid");
+        Jid result = item == null ? null : InvalidJid.getNullForInvalid(item.getAttributeAsJid("jid"));
         return result != null ? result : fallback;
     }
 
@@ -232,17 +233,25 @@ public class MessageParser extends AbstractParser implements OnMessagePacketRece
         if (x != null) {
             Element invite = x.findChild("invite");
             if (invite != null) {
-                Element pw = x.findChild("password");
-                Jid from = invite.getAttributeAsJid("from");
+                String password = x.findChildContent("password");
+                Jid from = InvalidJid.getNullForInvalid(invite.getAttributeAsJid("from"));
                 Contact contact = from == null ? null : account.getRoster().getContact(from);
-                return new Invite(message.getAttributeAsJid("from"), pw != null ? pw.getContent() : null, contact);
+                Jid room = InvalidJid.getNullForInvalid(message.getAttributeAsJid("from"));
+                if (room == null) {
+                    return null;
+                }
+                return new Invite(room, password, contact);
             }
         } else {
             x = message.findChild("x", "jabber:x:conference");
             if (x != null) {
-                Jid from = message.getAttributeAsJid("from");
+                Jid from = InvalidJid.getNullForInvalid(message.getAttributeAsJid("from"));
                 Contact contact = from == null ? null : account.getRoster().getContact(from);
-                return new Invite(x.getAttributeAsJid("jid"), x.getAttribute("password"), contact);
+                Jid room = InvalidJid.getNullForInvalid(x.getAttributeAsJid("jid"));
+                if (room == null) {
+                    return null;
+                }
+                return new Invite(room, x.getAttribute("password"), contact);
             }
         }
         return null;
@@ -810,7 +819,7 @@ public class MessageParser extends AbstractParser implements OnMessagePacketRece
         Element displayed = packet.findChild("displayed", "urn:xmpp:chat-markers:0");
         if (displayed != null) {
             final String id = displayed.getAttribute("id");
-            final Jid sender = displayed.getAttributeAsJid("sender");
+            final Jid sender = InvalidJid.getNullForInvalid(displayed.getAttributeAsJid("sender"));
             if (packet.fromAccount(account) && !selfAddressed) {
                 dismissNotification(account, counterpart, query);
             } else if (isTypeGroupChat) {
diff --git a/src/main/java/de/pixart/messenger/parser/PresenceParser.java b/src/main/java/de/pixart/messenger/parser/PresenceParser.java
index 8ce9dfbf7..15fb36372 100644
--- a/src/main/java/de/pixart/messenger/parser/PresenceParser.java
+++ b/src/main/java/de/pixart/messenger/parser/PresenceParser.java
@@ -19,6 +19,7 @@ import de.pixart.messenger.generator.PresenceGenerator;
 import de.pixart.messenger.services.XmppConnectionService;
 import de.pixart.messenger.utils.Namespace;
 import de.pixart.messenger.xml.Element;
+import de.pixart.messenger.xmpp.InvalidJid;
 import de.pixart.messenger.xmpp.OnPresencePacketReceived;
 import de.pixart.messenger.xmpp.pep.Avatar;
 import de.pixart.messenger.xmpp.stanzas.PresencePacket;
@@ -66,7 +67,7 @@ public class PresenceParser extends AbstractParser implements
                     if (item != null && !from.isBareJid()) {
                         mucOptions.setError(MucOptions.Error.NONE);
                         MucOptions.User user = parseItem(conversation, item, from);
-                        if (codes.contains(MucOptions.STATUS_CODE_SELF_PRESENCE) || (codes.contains(MucOptions.STATUS_CODE_ROOM_CREATED) && jid.equals(item.getAttributeAsJid("jid")))) {
+                        if (codes.contains(MucOptions.STATUS_CODE_SELF_PRESENCE) || (codes.contains(MucOptions.STATUS_CODE_ROOM_CREATED) && jid.equals(InvalidJid.getNullForInvalid(item.getAttributeAsJid("jid"))))) {
                             if (mucOptions.setOnline()) {
                                 mXmppConnectionService.getAvatarService().clear(mucOptions);
                             }
diff --git a/src/main/java/de/pixart/messenger/xml/Element.java b/src/main/java/de/pixart/messenger/xml/Element.java
index c2cb2a3b6..d9eb626d3 100644
--- a/src/main/java/de/pixart/messenger/xml/Element.java
+++ b/src/main/java/de/pixart/messenger/xml/Element.java
@@ -9,6 +9,7 @@ import java.util.List;
 import java.util.Locale;
 
 import de.pixart.messenger.utils.XmlHelper;
+import de.pixart.messenger.xmpp.InvalidJid;
 import rocks.xmpp.addr.Jid;
 
 public class Element {
@@ -151,7 +152,7 @@ public class Element {
             try {
                 return Jid.ofEscaped(jid);
             } catch (final IllegalArgumentException e) {
-                return null;
+                return new InvalidJid(jid);
             }
         }
         return null;
diff --git a/src/main/java/de/pixart/messenger/xmpp/InvalidJid.java b/src/main/java/de/pixart/messenger/xmpp/InvalidJid.java
new file mode 100644
index 000000000..fd4ca4b90
--- /dev/null
+++ b/src/main/java/de/pixart/messenger/xmpp/InvalidJid.java
@@ -0,0 +1,140 @@
+/*
+ * Copyright (c) 2018, Daniel Gultsch All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation and/or
+ * other materials provided with the distribution.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its contributors
+ * may be used to endorse or promote products derived from this software without
+ * specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package de.pixart.messenger.xmpp;
+
+import android.support.annotation.NonNull;
+
+import rocks.xmpp.addr.Jid;
+
+public class InvalidJid implements Jid {
+
+    private final String value;
+
+    public InvalidJid(String jid) {
+        this.value = jid;
+    }
+
+    @Override
+    @NonNull
+    public String toString() {
+        return value;
+    }
+
+    @Override
+    public boolean isFullJid() {
+        throw new AssertionError("Not implemented");
+    }
+
+    @Override
+    public boolean isBareJid() {
+        throw new AssertionError("Not implemented");
+    }
+
+    @Override
+    public Jid asBareJid() {
+        throw new AssertionError("Not implemented");
+    }
+
+    @Override
+    public Jid withLocal(CharSequence charSequence) {
+        throw new AssertionError("Not implemented");
+    }
+
+    @Override
+    public Jid withResource(CharSequence charSequence) {
+        throw new AssertionError("Not implemented");
+    }
+
+    @Override
+    public Jid atSubdomain(CharSequence charSequence) {
+        throw new AssertionError("Not implemented");
+    }
+
+    @Override
+    public String getLocal() {
+        throw new AssertionError("Not implemented");
+    }
+
+    @Override
+    public String getEscapedLocal() {
+        throw new AssertionError("Not implemented");
+    }
+
+    @Override
+    public String getDomain() {
+        throw new AssertionError("Not implemented");
+    }
+
+    @Override
+    public String getResource() {
+        throw new AssertionError("Not implemented");
+    }
+
+    @Override
+    public String toEscapedString() {
+        throw new AssertionError("Not implemented");
+    }
+
+    @Override
+    public int length() {
+        return value.length();
+    }
+
+    @Override
+    public char charAt(int index) {
+        return value.charAt(index);
+    }
+
+    @Override
+    public CharSequence subSequence(int start, int end) {
+        return value.subSequence(start, end);
+    }
+
+    @Override
+    public int compareTo(@NonNull Jid o) {
+        throw new AssertionError("Not implemented");
+    }
+
+    public static Jid getNullForInvalid(Jid jid) {
+        if (jid != null && jid instanceof InvalidJid) {
+            return null;
+        } else {
+            return jid;
+        }
+    }
+
+    public static boolean isValid(Jid jid) {
+        if (jid != null && jid instanceof InvalidJid) {
+            return false;
+        } else {
+            return true;
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/de/pixart/messenger/xmpp/XmppConnection.java b/src/main/java/de/pixart/messenger/xmpp/XmppConnection.java
index 867fb824e..775f7b430 100644
--- a/src/main/java/de/pixart/messenger/xmpp/XmppConnection.java
+++ b/src/main/java/de/pixart/messenger/xmpp/XmppConnection.java
@@ -5,6 +5,7 @@ import android.graphics.Bitmap;
 import android.graphics.BitmapFactory;
 import android.os.SystemClock;
 import android.security.KeyChain;
+import android.support.annotation.NonNull;
 import android.util.Base64;
 import android.util.Log;
 import android.util.Pair;
@@ -189,6 +190,25 @@ public class XmppConnection implements Runnable {
         mXmppConnectionService = service;
     }
 
+    private static void fixResource(Context context, Account account) {
+        String resource = account.getResource();
+        int fixedPartLength = context.getString(R.string.app_name).length() + 1; //include the trailing dot
+        int randomPartLength = 4; // 3 bytes
+        if (resource != null && resource.length() > fixedPartLength + randomPartLength) {
+            if (validBase64(resource.substring(fixedPartLength, fixedPartLength + randomPartLength))) {
+                account.setResource(resource.substring(0, fixedPartLength + randomPartLength));
+            }
+        }
+    }
+
+    private static boolean validBase64(String input) {
+        try {
+            return Base64.decode(input, Base64.URL_SAFE).length == 3;
+        } catch (Throwable throwable) {
+            return false;
+        }
+    }
+
     protected void changeStatus(final Account.State nextStatus) {
         synchronized (this) {
             this.mThread = Thread.currentThread();
@@ -690,8 +710,8 @@ public class XmppConnection implements Runnable {
         }
     }
 
-    private Element processPacket(final Tag currentTag, final int packetType)
-            throws XmlPullParserException, IOException {
+    private @NonNull
+    Element processPacket(final Tag currentTag, final int packetType) throws XmlPullParserException, IOException {
         Element element;
         switch (packetType) {
             case PACKET_IQ:
@@ -704,7 +724,7 @@ public class XmppConnection implements Runnable {
                 element = new PresencePacket();
                 break;
             default:
-                return null;
+                throw new AssertionError("Should never encounter invalid type");
         }
         element.setAttributes(currentTag.getAttributes());
         Tag nextTag = tagReader.readTag();
@@ -748,8 +768,9 @@ public class XmppConnection implements Runnable {
     private void processIq(final Tag currentTag) throws XmlPullParserException, IOException {
         final IqPacket packet = (IqPacket) processPacket(currentTag, PACKET_IQ);
 
-        if (packet.getId() == null) {
-            return; // an iq packet without id is definitely invalid
+        if (!packet.valid()) {
+            Log.e(Config.LOGTAG, "encountered invalid iq from='" + packet.getFrom() + "' to='" + packet.getTo() + "'");
+            return;
         }
 
         if (packet instanceof JinglePacket) {
@@ -793,11 +814,19 @@ public class XmppConnection implements Runnable {
 
     private void processMessage(final Tag currentTag) throws XmlPullParserException, IOException {
         final MessagePacket packet = (MessagePacket) processPacket(currentTag, PACKET_MESSAGE);
+        if (!packet.valid()) {
+            Log.e(Config.LOGTAG, "encountered invalid message from='" + packet.getFrom() + "' to='" + packet.getTo() + "'");
+            return;
+        }
         this.messageListener.onMessagePacketReceived(account, packet);
     }
 
     private void processPresence(final Tag currentTag) throws XmlPullParserException, IOException {
         PresencePacket packet = (PresencePacket) processPacket(currentTag, PACKET_PRESENCE);
+        if (!packet.valid()) {
+            Log.e(Config.LOGTAG, "encountered invalid presence from='" + packet.getFrom() + "' to='" + packet.getTo() + "'");
+            return;
+        }
         this.presenceListener.onPresencePacketReceived(account, packet);
     }
 
@@ -1257,7 +1286,7 @@ public class XmppConnection implements Runnable {
                     final List<Element> elements = packet.query().getChildren();
                     for (final Element element : elements) {
                         if (element.getName().equals("item")) {
-                            final Jid jid = element.getAttributeAsJid("jid");
+                            final Jid jid = InvalidJid.getNullForInvalid(element.getAttributeAsJid("jid"));
                             if (jid != null && !jid.equals(account.getServer())) {
                                 items.add(jid);
                             }
@@ -1331,25 +1360,6 @@ public class XmppConnection implements Runnable {
         return mXmppConnectionService.getString(R.string.app_name) + '.' + nextRandomId(true);
     }
 
-    private static void fixResource(Context context, Account account) {
-        String resource = account.getResource();
-        int fixedPartLength = context.getString(R.string.app_name).length() + 1; //include the trailing dot
-        int randomPartLength = 4; // 3 bytes
-        if (resource != null && resource.length() > fixedPartLength + randomPartLength) {
-            if (validBase64(resource.substring(fixedPartLength, fixedPartLength + randomPartLength))) {
-                account.setResource(resource.substring(0, fixedPartLength + randomPartLength));
-            }
-        }
-    }
-
-    private static boolean validBase64(String input) {
-        try {
-            return Base64.decode(input, Base64.URL_SAFE).length == 3;
-        } catch (Throwable throwable) {
-            return false;
-        }
-    }
-
     private String nextRandomId() {
         return nextRandomId(false);
     }
diff --git a/src/main/java/de/pixart/messenger/xmpp/jingle/JingleCandidate.java b/src/main/java/de/pixart/messenger/xmpp/jingle/JingleCandidate.java
index 9f163d5d9..e47b01d89 100644
--- a/src/main/java/de/pixart/messenger/xmpp/jingle/JingleCandidate.java
+++ b/src/main/java/de/pixart/messenger/xmpp/jingle/JingleCandidate.java
@@ -4,6 +4,7 @@ import java.util.ArrayList;
 import java.util.List;
 
 import de.pixart.messenger.xml.Element;
+import de.pixart.messenger.xmpp.InvalidJid;
 import rocks.xmpp.addr.Jid;
 
 public class JingleCandidate {
@@ -108,7 +109,7 @@ public class JingleCandidate {
         JingleCandidate parsedCandidate = new JingleCandidate(
                 candidate.getAttribute("cid"), false);
         parsedCandidate.setHost(candidate.getAttribute("host"));
-        parsedCandidate.setJid(candidate.getAttributeAsJid("jid"));
+        parsedCandidate.setJid(InvalidJid.getNullForInvalid(candidate.getAttributeAsJid("jid")));
         parsedCandidate.setType(candidate.getAttribute("type"));
         parsedCandidate.setPriority(Integer.parseInt(candidate
                 .getAttribute("priority")));
diff --git a/src/main/java/de/pixart/messenger/xmpp/stanzas/AbstractAcknowledgeableStanza.java b/src/main/java/de/pixart/messenger/xmpp/stanzas/AbstractAcknowledgeableStanza.java
index 22d035e6e..e795b40fd 100644
--- a/src/main/java/de/pixart/messenger/xmpp/stanzas/AbstractAcknowledgeableStanza.java
+++ b/src/main/java/de/pixart/messenger/xmpp/stanzas/AbstractAcknowledgeableStanza.java
@@ -1,6 +1,7 @@
 package de.pixart.messenger.xmpp.stanzas;
 
 import de.pixart.messenger.xml.Element;
+import de.pixart.messenger.xmpp.InvalidJid;
 
 abstract public class AbstractAcknowledgeableStanza extends AbstractStanza {
 
@@ -28,4 +29,8 @@ abstract public class AbstractAcknowledgeableStanza extends AbstractStanza {
         }
         return null;
     }
+
+    public boolean valid() {
+        return InvalidJid.isValid(getFrom()) && InvalidJid.isValid(getTo());
+    }
 }
diff --git a/src/main/java/de/pixart/messenger/xmpp/stanzas/AbstractStanza.java b/src/main/java/de/pixart/messenger/xmpp/stanzas/AbstractStanza.java
index 58d2a8b68..ee0884aa6 100644
--- a/src/main/java/de/pixart/messenger/xmpp/stanzas/AbstractStanza.java
+++ b/src/main/java/de/pixart/messenger/xmpp/stanzas/AbstractStanza.java
@@ -31,20 +31,23 @@ public class AbstractStanza extends Element {
     }
 
     public boolean fromServer(final Account account) {
-        return getFrom() == null
-                || getFrom().equals(Jid.of(account.getServer()))
-                || getFrom().equals(account.getJid().asBareJid())
-                || getFrom().equals(account.getJid());
+        final Jid from = getFrom();
+        return from == null
+                || from.equals(Jid.of(account.getServer()))
+                || from.equals(account.getJid().asBareJid())
+                || from.equals(account.getJid());
     }
 
     public boolean toServer(final Account account) {
-        return getTo() == null
-                || getTo().equals(Jid.of(account.getServer()))
-                || getTo().equals(account.getJid().asBareJid())
-                || getTo().equals(account.getJid());
+        final Jid to = getTo();
+        return to == null
+                || to.equals(Jid.of(account.getServer()))
+                || to.equals(account.getJid().asBareJid())
+                || to.equals(account.getJid());
     }
 
     public boolean fromAccount(final Account account) {
-        return getFrom() != null && getFrom().asBareJid().equals(account.getJid().asBareJid());
+        final Jid from = getFrom();
+        return from != null && from.asBareJid().equals(account.getJid().asBareJid());
     }
 }
diff --git a/src/main/java/de/pixart/messenger/xmpp/stanzas/IqPacket.java b/src/main/java/de/pixart/messenger/xmpp/stanzas/IqPacket.java
index 2efc948f4..5f4e39eca 100644
--- a/src/main/java/de/pixart/messenger/xmpp/stanzas/IqPacket.java
+++ b/src/main/java/de/pixart/messenger/xmpp/stanzas/IqPacket.java
@@ -66,4 +66,10 @@ public class IqPacket extends AbstractAcknowledgeableStanza {
         return packet;
     }
 
+    @Override
+    public boolean valid() {
+        String id = getId();
+        return id != null && super.valid();
+    }
+
 }