Quote null characters in regexps, IE does not like them.

lib/compiler.js

@@ -135,6 +135,7 @@ PEG.RegExpUtils = {
     /* Based on ECMA-262, 5th ed., 7.8.5 & 15.10.1. */
     return s
       .replace(/\\/g, '\\\\')        // backslash
+      .replace(/\0/g, '\\0')         // null, IE needs this
       .replace(/\//g, '\\/')         // closing slash
       .replace(/]/g, '\\]')          // closing bracket
       .replace(/-/g, '\\-')          // dash

test/compiler-test.js

@@ -112,8 +112,8 @@ test("quoteForClass", function() {
   strictEqual(PEG.RegExpUtils.quoteForClass(""), '');
   strictEqual(PEG.RegExpUtils.quoteForClass("abcd"), 'abcd');
   strictEqual(
-    PEG.RegExpUtils.quoteForClass("\\/]-\r\u2028\u2029\n\\/]-\r\u2028\u2029\n"),
-    '\\\\\\/\\]\\-\\r\\u2028\\u2029\\n\\\\\\/\\]\\-\\r\\u2028\\u2029\\n'
+    PEG.RegExpUtils.quoteForClass("\\\0/]-\r\u2028\u2029\n\\\0/]-\r\u2028\u2029\n"),
+    '\\\\\\0\\/\\]\\-\\r\\u2028\\u2029\\n\\\\\\0\\/\\]\\-\\r\\u2028\\u2029\\n'
   );
 });
 

test/metagrammar-test.js

@@ -299,8 +299,8 @@ with (PEG.Grammar) {
   test("parses bracketDelimitedCharacter", function() {
     grammarParserParses("start: [a]",       classGrammar("a"));
     grammarParserParses("start: [\\n]",     classGrammar("\\n"));
-    grammarParserParses("start: [\\0]",     classGrammar("\0"));
-    grammarParserParses("start: [\\x00]",   classGrammar("\x00"));
+    grammarParserParses("start: [\\0]",     classGrammar("\\0"));
+    grammarParserParses("start: [\\x00]",   classGrammar("\\0"));
     grammarParserParses("start: [\\u0120]", classGrammar("\u0120"));
     grammarParserParses("start: [\\\n]",    classGrammar("\\n"));
   });