- get a local reference to the file read stream in case the 'unpipe' …

…event nulls out the instance reference during the while loop

lib/server/command_processor.js

@@ -145,7 +145,8 @@ class CommandProcessor extends Duplex {
         if(this[kReadStream] === null || this[kSource] === null) return;
 
         let chunk;
-        while((chunk = this[kReadStream].read()) !== null) {
+        const rs = this[kReadStream];
+        while((chunk = rs.read()) !== null) {
             this._sendFileQueueChunkReads++;
             this._sendFileQueueReadBytes += chunk.length;
             if(!this.push(chunk, 'ascii')) break;