zlib: do not leak on destroy

PR-URL: #23734
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>

Author: mafintosh

lib/zlib.js

@@ -427,6 +427,11 @@ Zlib.prototype.close = function close(callback) {
 this.destroy();
 };
 
+Zlib.prototype._destroy=function_destroy(err,callback){
+_close(this);
+callback(err);
+};
+
 Zlib.prototype._transform=function_transform(chunk,encoding,cb){
 varflushFlag=this._defaultFlushFlag;
 // We use a 'fake' zero-length chunk to carry information about flushes from
@@ -589,6 +594,10 @@ function processCallback() {
 assert(false,'have should not go down');
 }
 
+if(self.destroyed){
+return;
+}
+
 // exhausted the output buffer, or used all the input create a new one.
 if(availOutAfter===0||self._outOffset>=self._chunkSize){
 handle.availOutBefore=self._chunkSize;

test/parallel/test-zlib-close-in-ondata.js

@@ -0,0 +1,10 @@
+'use strict';
+
+constcommon=require('../common');
+constzlib=require('zlib');
+
+constts=zlib.createGzip();
+constbuf=Buffer.alloc(1024*1024*20);
+
+ts.on('data',common.mustCall(()=>ts.close()));
+ts.end(buf);

test/parallel/test-zlib-destroy.js

@@ -0,0 +1,13 @@
+'use strict';
+
+require('../common');
+
+constassert=require('assert');
+constzlib=require('zlib');
+
+// verify that the zlib transform does clean up
+// the handle when calling destroy.
+
+constts=zlib.createGzip();
+ts.destroy();
+assert.strictEqual(ts._handle,null);