From f47da5c6828ac072646b89c99e6398006a434628 Mon Sep 17 00:00:00 2001
From: David Majda <david@majda.cz>
Date: Tue, 6 Mar 2012 08:46:28 +0100
Subject: [PATCH] Fix a bug in param name fixup code for sequences

---
 src/passes.js       |  2 +-
 test/passes-test.js | 10 ++++++++++
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/passes.js b/src/passes.js
index 4cd19cf..773c40f 100644
--- a/src/passes.js
+++ b/src/passes.js
@@ -364,7 +364,7 @@ PEG.compiler.passes = {
 
           function fixup(name) {
             each(pluck(node.elements, "resultVar"), function(resultVar, i) {
-              if (env[name].substr(0, resultVar.length) === resultVar) {
+              if ((new RegExp("^" + resultVar + "(\\[\\d+\\])*$")).test(env[name])) {
                 env[name] = node.resultVar + "[" + i + "]"
                           + env[name].substr(resultVar.length);
               }
diff --git a/test/passes-test.js b/test/passes-test.js
index 46ab528..9e9104b 100644
--- a/test/passes-test.js
+++ b/test/passes-test.js
@@ -579,6 +579,16 @@ test("computes params", function() {
         d: "result0[1][2]",
         e: "result0[2]"
       }
+    },
+    /*
+     * Regression tests for a bug where e.g. resultVar names like |result10|
+     * were incorrectly treated as names derived from |result1|, leading to
+     * incorrect substitution.
+     */
+    {
+      grammar:   'start = ("a" "b" "c" "d" "e" "f" "g" "h" "i" j:"j" { })*',
+      extractor: extractExpression,
+      params:    { j: "result1[9]" } // Buggy code put "result1[0]0" here.
     }
   ];