From aa32876715da8e7f148e057d0bf1d9d5af5b6f84 Mon Sep 17 00:00:00 2001
From: Marco Castelluccio <mcastelluccio@mozilla.com>
Date: Thu, 25 Sep 2014 18:14:38 -0700
Subject: [PATCH] Override entire ByteArrayInputStream class in JS

---
 override.js | 99 ++++++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 87 insertions(+), 12 deletions(-)

diff --git a/override.js b/override.js
index 0a878f77..6b8b5edc 100644
--- a/override.js
+++ b/override.js
@@ -40,18 +40,93 @@ Override["java/lang/Math.min.(II)I"] = function(ctx, stack) {
   stack.push(a <= b ? a : b);
 }
 
+Override["java/io/ByteArrayInputStream.<init>.([B)V"] = function(ctx, stack) {
+  var buf = stack.pop(), _this = stack.pop();
+
+  if (!buf) {
+    ctx.raiseExceptionAndYield("java/lang/NullPointerException");
+  }
+
+  _this.buf = buf;
+  _this.pos = _this.mark = 0;
+  _this.count = buf.length;
+}
+
+Override["java/io/ByteArrayInputStream.<init>.([BII)V"] = function(ctx, stack) {
+  var length = stack.pop(), offset = stack.pop(), buf = stack.pop(), _this = stack.pop();
+
+  if (!buf) {
+    ctx.raiseExceptionAndYield("java/lang/NullPointerException");
+  }
+
+  _this.buf = buf;
+  _this.pos = _this.mark = offset;
+  _this.count = (offset + length <= buf.length) ? (offset + length) : buf.length;
+}
+
 Override["java/io/ByteArrayInputStream.read.()I"] = function(ctx, stack) {
   var _this = stack.pop();
-
-  var pos = _this.class.getField("pos", "I").get(_this);
-  var count = _this.class.getField("count", "I").get(_this);
-  var buf = _this.class.getField("buf", "[B").get(_this);
-
-  if (pos < count) {
-      var value = buf[pos++] & 0xFF;
-      _this.class.getField("pos", "I").set(_this, pos);
-      stack.push(value);
-  } else {
-      stack.push(-1);
-  }
+  stack.push((_this.pos < _this.count) ? (_this.buf[_this.pos++] & 0xFF) : -1);
+}
+
+Override["java/io/ByteArrayInputStream.read.([BII)I"] = function(ctx, stack) {
+  var len = stack.pop(), off = stack.pop(), b = stack.pop(), _this = stack.pop();
+
+  if (!b) {
+    ctx.raiseExceptionAndYield("java/lang/NullPointerException");
+  } else if ((off < 0) || (off > b.length) || (len < 0) ||
+             ((off + len) > b.length) || ((off + len) < 0)) {
+    ctx.raiseExceptionAndYield("java/lang/IndexOutOfBoundsException");
+  }
+
+  if (_this.pos >= _this.count) {
+    stack.push(-1);
+    return;
+  }
+  if (_this.pos + len > _this.count) {
+    len = _this.count - _this.pos;
+  }
+  if (len <= 0) {
+    stack.push(0);
+    return;
+  }
+
+  b.set(_this.buf.subarray(_this.pos, _this.pos + len), off);
+
+  _this.pos += len;
+  stack.push(len);
+}
+
+Override["java/io/ByteArrayInputStream.skip.(J)J"] = function(ctx, stack) {
+  var nLong = stack.pop2(), _this = stack.pop();
+
+  var n = nLong.toNumber();
+
+  if (_this.pos + n > _this.count) {
+      n = _this.count - _this.pos;
+  }
+
+  if (n < 0) {
+      stack.push2(Long.fromNumber(0));
+      return;
+  }
+
+  _this.pos += n;
+
+  stack.push2(nLong);
+}
+
+Override["java/io/ByteArrayInputStream.available.()I"] = function(ctx, stack) {
+  var _this = stack.pop();
+  stack.push(_this.count - _this.pos);
+}
+
+Override["java/io/ByteArrayInputStream.mark.(I)V"] = function(ctx, stack) {
+  var readAheadLimit = stack.pop(), _this = stack.pop();
+  _this.mark = _this.pos;
+}
+
+Override["java/io/ByteArrayInputStream.reset.()V"] = function(ctx, stack) {
+  var _this = stack.pop();
+  _this.pos = _this.mark;
 }