2 files changed, 13 insertions, 2 deletions
diff --git a/Sluift/client.cpp b/Sluift/client.cpp
index 0dc7014..75f675d 100644
--- a/Sluift/client.cpp
+++ b/Sluift/client.cpp
@@ -360,2 +360,5 @@ SLUIFT_LUA_FUNCTION_WITH_HELP(
     message->setType(type);
+    if (!getClient(L)->getClient()->isAvailable()) {
+        throw Lua::Exception("Trying to send message while client is offline.");
+    }
     getClient(L)->getClient()->sendMessage(message);
@@ -405,3 +408,5 @@ SLUIFT_LUA_FUNCTION_WITH_HELP(
     }
-
+    if (!getClient(L)->getClient()->getPresenceSender()->isAvailable()) {
+        throw Lua::Exception("Trying to send presence while client is offline.");
+    }
     getClient(L)->getClient()->getPresenceSender()->sendPresence(presence);
@@ -491,3 +496,5 @@ SLUIFT_LUA_FUNCTION_WITH_HELP(
     Sluift::globals.eventLoop.runOnce();
-
+    if (!getClient(L)->getClient()->isAvailable()) {
+        throw Lua::Exception("Trying to send data while client is offline.");
+    }
     getClient(L)->getClient()->sendData(std::string(Lua::checkString(L, 2)));
diff --git a/Swiften/Client/CoreClient.cpp b/Swiften/Client/CoreClient.cpp
index 3c7902e..1de1d61 100644
--- a/Swiften/Client/CoreClient.cpp
+++ b/Swiften/Client/CoreClient.cpp
@@ -392,2 +392,6 @@ void CoreClient::sendPresence(std::shared_ptr<Presence> presence) {
 void CoreClient::sendData(const std::string& data) {
+    if (!sessionStream_) {
+        SWIFT_LOG(warning) << "Client: Trying to send data while disconnected." << std::endl;
+        return;
+    }
     sessionStream_->writeData(data);