From cf996d2c4a9abf335bbcb7829ed6d7a67b807398 Mon Sep 17 00:00:00 2001
From: Michael Ficarra <git@michael.ficarra.me>
Date: Mon, 3 Oct 2011 06:43:00 -0400
Subject: [PATCH] quick fix to part of new issue in #1099:

`not in []` unconditionally compiled to `false`
---
 lib/coffee-script/nodes.js |  2 +-
 src/nodes.coffee           |  2 +-
 test/operators.coffee      | 11 +++++++----
 3 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/lib/coffee-script/nodes.js b/lib/coffee-script/nodes.js
index 322c1d23..07ee1224 100644
--- a/lib/coffee-script/nodes.js
+++ b/lib/coffee-script/nodes.js
@@ -1892,6 +1892,7 @@
 
     In.prototype.compileOrTest = function(o) {
       var cmp, cnj, i, item, ref, sub, tests, _ref2, _ref3;
+      if (this.array.base.objects.length === 0) return "" + (!!this.negated);
       _ref2 = this.object.cache(o, LEVEL_OP), sub = _ref2[0], ref = _ref2[1];
       _ref3 = this.negated ? [' !== ', ' && '] : [' === ', ' || '], cmp = _ref3[0], cnj = _ref3[1];
       tests = (function() {
@@ -1904,7 +1905,6 @@
         }
         return _results;
       }).call(this);
-      if (tests.length === 0) return 'false';
       tests = tests.join(cnj);
       if (o.level < LEVEL_OP) {
         return tests;
diff --git a/src/nodes.coffee b/src/nodes.coffee
index 07ceb8d3..08eedcf5 100644
--- a/src/nodes.coffee
+++ b/src/nodes.coffee
@@ -1408,11 +1408,11 @@ exports.In = class In extends Base
     @compileLoopTest o
 
   compileOrTest: (o) ->
+    return "#{!!@negated}" if @array.base.objects.length is 0
     [sub, ref] = @object.cache o, LEVEL_OP
     [cmp, cnj] = if @negated then [' !== ', ' && '] else [' === ', ' || ']
     tests = for item, i in @array.base.objects
       (if i then ref else sub) + cmp + item.compile o, LEVEL_ACCESS
-    return 'false' if tests.length is 0
     tests = tests.join cnj
     if o.level < LEVEL_OP then tests else "(#{tests})"
 
diff --git a/test/operators.coffee b/test/operators.coffee
index 79d77134..2391ee9e 100644
--- a/test/operators.coffee
+++ b/test/operators.coffee
@@ -199,16 +199,19 @@ test "#1100: precedence in or-test compilation of `in`", ->
 
 test "#1630: `in` should check `hasOwnProperty`", ->
   ok undefined not in length: 1
-  
+
 test "#1714: lexer bug with raw range `for` followed by `in`", ->
   0 for [1..2]
   ok not ('a' in ['b'])
-  
+
   0 for [1..2]; ok not ('a' in ['b'])
-  
+
   0 for [1..10] # comment ending
   ok not ('a' in ['b'])
 
+test "#1099: statically determined `not in []` reporting incorrect result", ->
+  ok 0 not in []
+
 
 # Chained Comparison
 
@@ -259,4 +262,4 @@ test "#1102: String literal prevents line continuation", ->
 
 test "#1703, ---x is invalid JS", ->
   x = 2
-  eq (- --x), -1
\ No newline at end of file
+  eq (- --x), -1