Prevent a crash when client issues EXEC without MULTI

CHANGELOG.md

@@ -5,6 +5,9 @@ All notable changes to this project will be documented in this file.
 ### Added
 - Command `hclone` for creating identical copies of entire hashes.
 
+### Fixed
+- An `EXEC` when not inside a `MULTI` would cause a crash.
+
 ## 0.2.9 (2018-07-16)
 ### Added
 - Commands `convert-string-to-int`, `convert-int-to-string` to convert between

qclient @ 630fe4d1

-Subproject commit 1ad54a7631b7a7e6db4c14fb4a33596b838724a6
+Subproject commit 630fe4d17f673bfc476f10bbaf7b6ea82d0db0c3

src/Connection.cc

@@ -244,6 +244,12 @@ LinkStatus Connection::processRequests(Dispatcher *dispatcher, const InFlightTra
       continue;
     }
 
+    // EXEC without MULTI?
+    if(currentRequest.getCommand() == RedisCommand::EXEC && !multiHandler.active()) {
+      this->err("EXEC without MULTI");
+      continue;
+    }
+
     if(currentRequest.getCommand() == RedisCommand::TX_READWRITE) {
       multiHandler.finalizePhantomTransaction(dispatcher, this);
       dispatcher->dispatch(this, currentRequest);

test/multi.cc

@@ -117,6 +117,11 @@ TEST_F(Multi, HandlerBasicSanity) {
   ASSERT_REPLY(replies[1], "QUEUED");
   ASSERT_REPLY(replies[2], "OK");
   ASSERT_REPLY(replies[3], "v1");
+
+  // EXEC without MULTI
+  replies.clear();
+  ASSERT_REPLY(tunnel(leaderID)->exec("EXEC"), "ERR EXEC without MULTI");
+  ASSERT_REPLY(tunnel(leaderID)->exec("HGET", "myhash", "f1"), "v1");
 }
 
 TEST_F(Multi, WithRaft) {