Found and fixed the "Mother Fucker of a Bug(tm)" that was causing

Zyraxxis to hork.
Deep within our streaming code, ArrayMask objects were being created with
zero length when streaming non-final arrays with a zero length. This tickled
a "feature" of Adobe's IDataInput code, which reads *all available bytes*
if you pass readBytes() a length of 0.
What's really annoying is that this worked fine if you were notified
of the zero-length array via a PropertySetEvent, because that event
would come in on its own frame and so if the array's length was zero then
there were no more bytes to read. But if you entered a game and had
to receive all the usercode properties at once, it booched.
There are clumps of my pulled-out hair all around my desk from that.
And: this is ultimately my own fault, as my old code didn't handle the
case of the passed-in ByteArray having 0 length.


git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@4900 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/as/com/threerings/io/ObjectInputStream.as

@@ -206,16 +206,18 @@ public class ObjectInputStream
     }
 
     public function readBytes (bytes :ByteArray, offset :uint = 0,
-            length :uint = 0) :void
+            length :int = -1) :void
         //throws IOError
     {
-        // IDataInput reads all available bytes if a length is not passed
-        // in. Protect against an easy error to make by using the length of
-        // the array
-        if (length === 0) {
-            length = bytes.length;
+        // if no length specified then fill the ByteArray
+        if (length == -1) {
+            length = bytes.length - offset;
+        }
+        // And, if we really want to read 0 bytes then just don't do anything, because an
+        // IDataInput will read *all available bytes* when the specified length is 0.
+        if (length > 0) {
+            _source.readBytes(bytes, offset, length);
         }
-        _source.readBytes(bytes, offset, length);
     }
 
     public function readDouble () :Number