Check buffer/skip size for undefined and NaN.

Manually coerce to 0 if found.  Previously the offset variable would be
corrupted to NaN causing all following word*() functions to mysteriously store
null.

Author: wanderview

index.js

@@ -131,6 +131,8 @@ exports.stream = function (input) {
         self.buffer = function (name, bytes) {
             if (typeof bytes === 'string') {
                 bytes = vars.get(bytes);
+            } else if (bytes === undefined || bytes !== bytes) {
+                bytes = 0;
             }
 
             getBytes(bytes, function (buf) {
@@ -142,6 +144,8 @@ exports.stream = function (input) {
         self.skip = function (bytes) {
             if (typeof bytes === 'string') {
                 bytes = vars.get(bytes);
+            } else if (bytes === undefined || bytes !== bytes) {
+                bytes = 0;
             }
 
             getBytes(bytes, function () {
@@ -272,6 +276,8 @@ exports.parse = function parse (buffer) {
     self.buffer = function (name, size) {
         if (typeof size === 'string') {
             size = vars.get(size);
+        } else if (size === undefined || size !== size) {
+            size = 0;
         }
         var buf = buffer.slice(offset, Math.min(buffer.length, offset + size));
         offset += size;
@@ -283,6 +289,8 @@ exports.parse = function parse (buffer) {
     self.skip = function (bytes) {
         if (typeof bytes === 'string') {
             bytes = vars.get(bytes);
+        } else if (bytes === undefined || bytes !== bytes) {
+            bytes = 0;
         }
         offset += bytes;
 

test/parse.js

@@ -52,3 +52,17 @@ test('loop', function (t) {
         y : 9,
     });
 });
+
+test('NaN', function(t) {
+    t.plan(3);
+    var res = binary.parse(new Buffer([ 106, 35 ]))
+        .buffer('a', NaN)
+        .word8('b')
+        .skip(NaN)
+        .word8('c')
+        .vars
+    ;
+    t.equal(res.a.length, 0);
+    t.equal(res.b, 106);
+    t.equal(res.c, 35);
+});