http: free parser on keepalive

Free parser when putting socket back in the agent
keep alive free list.

Fixes: nodejs#29394

lib/_http_client.js

@@ -409,7 +409,6 @@ function socketCloseListener() {
 
   // NOTE: It's important to get parser here, because it could be freed by
   // the `socketOnData`.
-  const parser = socket.parser;
   const res = req.res;
   if (res) {
     // Socket closed before we emitted 'end' below.
@@ -443,10 +442,7 @@ function socketCloseListener() {
   if (req.outputData)
     req.outputData.length = 0;
 
-  if (parser) {
-    parser.finish();
-    freeParser(parser, req, socket);
-  }
+  freeSocket(req, socket);
 }
 
 function socketErrorListener(err) {
@@ -461,11 +457,7 @@ function socketErrorListener(err) {
     req.emit('error', err);
   }
 
-  const parser = socket.parser;
-  if (parser) {
-    parser.finish();
-    freeParser(parser, req, socket);
-  }
+  freeSocket(req, socket);
 
   // Ensure that no further data will come out of the socket
   socket.removeListener('data', socketOnData);
@@ -476,18 +468,14 @@ function socketErrorListener(err) {
 function socketOnEnd() {
   const socket = this;
   const req = this._httpMessage;
-  const parser = this.parser;
 
   if (!req.res && !req.socket._hadError) {
     // If we don't have a response then we know that the socket
     // ended prematurely and we need to emit an error on the request.
     req.socket._hadError = true;
     req.emit('error', connResetException('socket hang up'));
   }
-  if (parser) {
-    parser.finish();
-    freeParser(parser, req, socket);
-  }
+  freeSocket(req, this);
   socket.destroy();
 }
 
@@ -519,8 +507,7 @@ function socketOnData(d) {
     if (req.timeoutCb)
       socket.removeListener('timeout', req.timeoutCb);
 
-    parser.finish();
-    freeParser(parser, req, socket);
+    freeSocket(req, this);
 
     const bodyHead = d.slice(bytesParsed, d.length);
 
@@ -712,10 +699,19 @@ function emitFreeNT(req) {
   }
 
   if (req.socket) {
+    freeSocket(req, req.socket);
     req.socket.emit('free');
   }
 }
 
+function freeSocket(req, socket) {
+  const parser = socket.parser;
+  if (parser) {
+    parser.finish();
+    freeParser(parser, req, socket);
+  }
+}
+
 function tickOnSocket(req, socket) {
   const parser = parsers.alloc();
   req.socket = socket;