zlib: do not emit event on *Sync() methods

Asynchronous functions in `zlib` should not emit the close event.

This fixes an issue where asynchronous calls in a for loop could exhaust
memory because the pending event prevents the objects from being garbage
collected.

Fixes: https://github.com/nodejs/node/issues/1668
PR-URL: https://github.com/nodejs/node/pull/5707
Reviewed-By: jasnell - James M Snell <jasnell@gmail.com>
Reviewed-By: trevnorris - Trevor Norris <trev.norris@gmail.com>
Reviewed-By: Сковорода Никита Андреевич <chalkerx@gmail.com>

1 files changed, 11 insertions, 8 deletions

diff --git a/lib/zlib.js b/lib/zlib.js
index 0028c35d79..79c78ea4a5 100644
--- a/lib/zlib.js
+++ b/lib/zlib.js
@@ -454,18 +454,21 @@ Zlib.prototype.flush = function(kind, callback) {
 };
 
 Zlib.prototype.close = function(callback) {
+  _close(this, callback);
+  process.nextTick(emitCloseNT, this);
+};
+
+function _close(engine, callback) {
   if (callback)
     process.nextTick(callback);
 
-  if (this._closed)
+  if (engine._closed)
     return;
 
-  this._closed = true;
+  engine._closed = true;
 
-  this._handle.close();
-
-  process.nextTick(emitCloseNT, this);
-};
+  engine._handle.close();
+}
 
 function emitCloseNT(self) {
   self.emit('close');
@@ -535,12 +538,12 @@ Zlib.prototype._processChunk = function(chunk, flushFlag, cb) {
     }
 
     if (nread >= kMaxLength) {
-      this.close();
+      _close(this);
       throw new RangeError(kRangeErrorMessage);
     }
 
     var buf = Buffer.concat(buffers, nread);
-    this.close();
+    _close(this);
 
     return buf;
   }