Fixed fs.ReadStream() start: 0 bug

lib/fs.js

@@ -623,7 +623,7 @@ var ReadStream = fs.ReadStream = function(path, options) {
     this[key] = options[key];
   }
 
-  if (this.start || this.end) {
+  if (this.start !== undefined || this.end !== undefined) {
     if (this.start === undefined || this.end === undefined) {
       this.emit('error',
         new Error('Both start and end are needed for range streaming.'));
@@ -671,7 +671,7 @@ ReadStream.prototype._read = function () {
     allocNewPool();
   }
 
-  if(this.start && this.firstRead) {
+  if (this.start !== undefined && this.firstRead) {
     this.pos = this.start;
     this.firstRead = false;
   }
@@ -683,7 +683,7 @@ ReadStream.prototype._read = function () {
   var toRead = Math.min(pool.length - pool.used, this.bufferSize);
   var start = pool.used;
 
-  if(this.pos) {
+  if (this.pos !== undefined) {
     toRead = Math.min(this.end - this.pos + 1, toRead);
   }
 
@@ -721,7 +721,7 @@ ReadStream.prototype._read = function () {
 
   fs.read(self.fd, pool, pool.used, toRead, this.pos, afterRead);
 
-  if(self.pos) {
+  if (self.pos !== undefined) {
     self.pos += toRead;
   }
   pool.used += toRead;

test/simple/test-fs-read-stream.js

@@ -110,3 +110,14 @@ try {
 } catch(e) {
   assert.equal(e.message, 'Both start and end are needed for range streaming.');
 }
+
+var stream = fs.createReadStream(rangeFile, { start: 0, end: 0 });
+stream.data = '';
+
+stream.on('data', function(chunk){
+  stream.data += chunk;
+});
+
+stream.on('end', function(){
+  assert.equal('x', stream.data);
+});