Fixing Issue #589. Compound assignment to an operation should have lower precedence.

lib/command.js

@@ -218,7 +218,7 @@
     var o;
     optionParser = new optparse.OptionParser(SWITCHES, BANNER);
     o = (options = optionParser.parse(process.argv.slice(2, process.argv.length)));
-    options.compile = options.compile || !!o.output;
+    options.compile = options.compile || (!!o.output);
     options.run = !(o.compile || o.print || o.lint);
     options.print = !!(o.print || (o.eval || o.stdio && o.compile));
     return (sources = options.arguments);

lib/nodes.js

@@ -1288,6 +1288,9 @@
       first = _b[0];
       firstVar = _b[1];
       second = this.second.compile(o);
+      if (this.second instanceof OpNode) {
+        second = ("(" + (second) + ")");
+      }
       if (first.match(IDENTIFIER)) {
         o.scope.find(first);
       }
@@ -1672,7 +1675,7 @@
       return this;
     };
     IfNode.prototype.isStatement = function() {
-      return this.statement = this.statement || !!(this.tags.statement || this.bodyNode().isStatement() || (this.elseBody && this.elseBodyNode().isStatement()));
+      return this.statement = this.statement || (!!(this.tags.statement || this.bodyNode().isStatement() || (this.elseBody && this.elseBodyNode().isStatement())));
     };
     IfNode.prototype.compileCondition = function(o) {
       var _b, _c, _d, _e, cond;

src/nodes.coffee

@@ -1110,6 +1110,7 @@ exports.OpNode = class OpNode extends BaseNode
   compileAssignment: (o) ->
     [first, firstVar] = @first.compileReference o, precompile: yes, assignment: yes
     second = @second.compile o
+    second = "(#{second})" if @second instanceof OpNode
     o.scope.find(first) if first.match(IDENTIFIER)
     return "#{first} = #{ ExistenceNode.compileTest(o, literal(firstVar)) } ? #{firstVar} : #{second}" if @operator is '?='
     "#{first} = #{firstVar} #{ @operator.substr(0, 2) } #{second}"

test/test_operations.coffee

@@ -93,4 +93,10 @@ ok list.join(' ') is '0  5 10'
 count = 0
 
 list[key()] ?= 100
-ok list.join(' ') is '0 100 5 10'
+ok list.join(' ') is '0 100 5 10'
+
+
+# Ensure that RHS is treated as a group.
+a = b = false
+a and= b or true
+ok a is false