fixed a bug that compound assignments were declaring variables

lib/nodes.js

@@ -927,7 +927,7 @@
       if (!this.variable.isAssignable()) {
         throw SyntaxError("\"" + (this.variable.compile(o)) + "\" cannot be assigned.");
       }
-      if (!(isValue && (this.variable.hasProperties() || this.variable.namespaced))) {
+      if (!(this.context || isValue && (this.variable.namespaced || this.variable.hasProperties()))) {
         o.scope.find(name);
       }
       val = name + (" " + (this.context || '=') + " ") + val;
@@ -1001,7 +1001,7 @@
     Assign.prototype.compileConditional = function(o) {
       var _ref2, left, rite;
       _ref2 = this.variable.cacheReference(o), left = _ref2[0], rite = _ref2[1];
-      return new Op(this.context.slice(0, -1), left, new Assign(rite, this.value)).compile(o);
+      return new Op(this.context.slice(0, -1), left, new Assign(rite, this.value, '=')).compile(o);
     };
     return Assign;
   })();

src/nodes.coffee

@@ -764,7 +764,8 @@ exports.Assign = class Assign extends Base
     return "#{name}: #{val}" if @context is 'object'
     unless @variable.isAssignable()
       throw SyntaxError "\"#{ @variable.compile o }\" cannot be assigned."
-    o.scope.find name unless isValue and (@variable.hasProperties() or @variable.namespaced)
+    o.scope.find name unless @context or
+      isValue and (@variable.namespaced or @variable.hasProperties())
     val = name + " #{ @context or '=' } " + val
     if o.level <= LEVEL_LIST then val else "(#{val})"
 
@@ -833,7 +834,7 @@ exports.Assign = class Assign extends Base
   # more than once.
   compileConditional: (o) ->
     [left, rite] = @variable.cacheReference o
-    return new Op(@context.slice(0, -1), left, new Assign(rite, @value)).compile o
+    new Op(@context.slice(0, -1), left, new Assign(rite, @value, '=')).compile o
 
 #### Code
 

test/test_assignment.coffee

@@ -64,3 +64,7 @@ eq val, 'value'
 for nonref in ['""', '0', 'f()']
   try ok not CoffeeScript.compile "{k: #{nonref}} = v"
   catch e then eq e.message, "\"#{nonref}\" cannot be assigned."
+
+
+# Compound assignments should not declare.
+eq Math, (-> Math or= 0)()