Suspend registration on CAP REQ

Fix #1820

src/Client.cpp

@@ -808,6 +808,7 @@ void CClient::HandleCap(const CMessage& Message) {
             }
         }
     } else if (sSubCmd.Equals("REQ")) {
+        m_bInCap = true;
         VCString vsTokens;
         Message.GetParam(1).Split(" ", vsTokens, false);
 

test/integration/tests/core.cpp

@@ -733,5 +733,17 @@ TEST_F(ZNCTest, HashUpgrade) {
     client.Close();
 }
 
+TEST_F(ZNCTest, CapReqWithoutLs) {
+    auto znc = Run();
+    auto ircd = ConnectIRCd();
+
+    auto client = ConnectClient();
+    client.Write("CAP REQ nonono");
+    client.Write("PASS :hunter2");
+    client.Write("NICK nick");
+    client.Write("USER foo x x :x");
+    ASSERT_THAT(client.ReadRemainder().toStdString(), Not(HasSubstr("Welcome")));
+}
+
 }  // namespace
 }  // namespace znc_inttest