Handle empty files with fs.readFile

lib/fs.js

@@ -51,6 +51,10 @@ fs.readFile = function (path, encoding_, callback) {
       var buffer = new Buffer(size);
       var offset = 0;
       function doRead() {
+        if (size < 1) {
+          callback(null, buffer);
+          return;
+        }
         // position is offset or null so we can read files on unseekable mediums
         binding.read(fd, buffer, offset, size - offset, offset || null, function (err, amount) {
           if (err) {

test/simple/test-fs-readfile-empty.js

@@ -0,0 +1,10 @@
+require('../common');
+
+var
+  path = require('path'),
+  fs = require('fs'),
+  fn = path.join(fixturesDir, 'empty.txt');
+
+fs.readFile(fn, function(err, data) {
+  assert.ok(data);
+});