Harden a few builtins

src/uri.js

Index: src/uri.js
diff --git a/src/uri.js b/src/uri.js
index fb9742fa873d30ebccc7dae2560bdb89cc434ef8..a6b346f48d8dfd8b47c222bec8d60e2d636f4519 100644
--- a/src/uri.js
+++ b/src/uri.js
@@ -83,16 +83,18 @@ function URIHexCharsToCharCode(highChar, lowChar) {
 }
 
 
-function URIDecodeOctets(octets, result, index) {
-  if (!IS_STRING(result)) throw new $URIError("Internal error");
+// Users of this macro must ensure that OCTETS is an array and RESULT is a
+// sufficiently long two-byte sequential string.
+// INDEX will be modified as characters are added to RESULT.
+macro URI_DECODE_OCTETS(OCTETS, RESULT, INDEX)

[rossberg, 2014/05/21 14:30:15]

Let's at least add a comment that explains why this was done, and a TODO with
the plan to replace it with a scalable solution.

   var value;
-  var o0 = octets[0];
+  var o0 = OCTETS[0];
   if (o0 < 0x80) {
     value = o0;
   } else if (o0 < 0xc2) {
     throw new $URIError("URI malformed");
   } else {
-    var o1 = octets[1];
+    var o1 = OCTETS[1];
     if (o0 < 0xe0) {
       var a = o0 & 0x1f;
       if ((o1 < 0x80) || (o1 > 0xbf)) {
@@ -104,7 +106,7 @@ function URIDecodeOctets(octets, result, index) {
         throw new $URIError("URI malformed");
       }
     } else {
-      var o2 = octets[2];
+      var o2 = OCTETS[2];
       if (o0 < 0xf0) {
         var a = o0 & 0x0f;
         if ((o1 < 0x80) || (o1 > 0xbf)) {
@@ -120,7 +122,7 @@ function URIDecodeOctets(octets, result, index) {
           throw new $URIError("URI malformed");
         }
       } else {
-        var o3 = octets[3];
+        var o3 = OCTETS[3];
         if (o0 < 0xf8) {
           var a = (o0 & 0x07);
           if ((o1 < 0x80) || (o1 > 0xbf)) {
@@ -149,20 +151,12 @@ function URIDecodeOctets(octets, result, index) {
     throw new $URIError("URI malformed");
   }
   if (value < 0x10000) {
-    if (index < 0 || index >= result.length) {
-      throw new $URIError("Internal error");
-    }
-    %_TwoByteSeqStringSetChar(result, index++, value);
-    return index;
+    %_TwoByteSeqStringSetChar(RESULT, INDEX++, value);
   } else {
-    if (index < 0 || index >= result.length - 1) {
-      throw new $URIError("Internal error");
-    }
-    %_TwoByteSeqStringSetChar(result, index++, (value >> 10) + 0xd7c0);
-    %_TwoByteSeqStringSetChar(result, index++, (value & 0x3ff) + 0xdc00);
-    return index;
+    %_TwoByteSeqStringSetChar(RESULT, INDEX++, (value >> 10) + 0xd7c0);
+    %_TwoByteSeqStringSetChar(RESULT, INDEX++, (value & 0x3ff) + 0xdc00);
   }
-}
+endmacro
 
 
 // ECMA-262, section 15.1.3
@@ -248,7 +242,7 @@ function Decode(uri, reserved) {
           octets[i] = URIHexCharsToCharCode(uri.charCodeAt(++k),
                                             uri.charCodeAt(++k));
         }
-        index = URIDecodeOctets(octets, two_byte, index);
+        URI_DECODE_OCTETS(octets, two_byte, index);
       } else  if (reserved(cc)) {
         %_TwoByteSeqStringSetChar(two_byte, index++, 37);  // '%'.
         %_TwoByteSeqStringSetChar(two_byte, index++, uri.charCodeAt(k - 1));