Fix transaction queuing and pubsub count parsing

src/Handler.cpp

@@ -543,22 +543,6 @@ bool Handler::preHandleRequest(Request* req, const String& key)
     FuncCallTimer();
     auto c = req->connection();
     if (c && c->inTransaction()) {
-        switch (req->type()) {
-        case Command::Select:
-        case Command::Psubscribe:
-        case Command::Subscribe:
-            {
-                ResponsePtr res = ResponseAlloc::create();
-                char buf[128];
-                snprintf(buf, sizeof(buf), "forbid command \"%s\" in transaction",
-                        req->cmd());
-                res->setErr(buf);
-                handleResponse(nullptr, req, res);
-                return true;
-            }
-        default:
-            break;
-        }
         return false;
     }
     if (req->type() == Command::Msetnx && mProxy->isSplitMultiKey()) {
@@ -910,7 +894,8 @@ void Handler::handleResponse(ConnectConnection* s, Request* req, Response* res)
         res->adjustForLeader(req);
     }
     req->setResponse(res);
-    if (c->send(this, req, res)) {
+    // Always trigger write event for error responses to ensure they're sent immediately
+    if (c->send(this, req, res) || res->isError()) {
         addPostEvent(c, Multiplexor::WriteEvent);
     }
     long elapsed = Util::elapsedUSec() - req->createTime();

src/Subscribe.cpp

@@ -41,21 +41,34 @@ SubscribeParser::Status SubscribeParser::parse(const Segment& body, int& chs)
         st = String;
     }
     if (chs < 0) {
+        // Parse count from the end of the response
+        // Format: *3\r\n$N\r\nsubscribe\r\n$M\r\n<channel>\r\n:<count>\r\n
+        // The count is always the last integer after a colon
         int len = body.length();
-        int tailLen = len < 64 ? len : 64;
+        // Look at the tail, but use a larger buffer for long channel names
+        int tailLen = len < 256 ? len : 256;
         Segment tmp(body);
         tmp.rewind();
         if (len > tailLen) {
             tmp.use(len - tailLen);
         }
-        char buf[64 + 1];
+        char buf[256 + 1];
         int n = tmp.dump(buf, tailLen);
         buf[n] = '\0';
+        // Search backwards for colon followed by digits
         const char* p = buf + n;
         while (p > buf) {
             if (*--p == ':') {
-                chs = atoi(p + 1);
+                // Found colon, parse the number after it
-                break;
+                const char* numStart = p + 1;
+                // Skip whitespace
+                while (*numStart == ' ' || *numStart == '\t') {
+                    numStart++;
+                }
+                if (*numStart >= '0' && *numStart <= '9') {
+                    chs = atoi(numStart);
+                    break;
+                }
             }
         }
     }