Fixes #2621 -- buggy function parameter name detection with complex destructuring in param list.

lib/coffee-script/nodes.js

@@ -1919,7 +1919,7 @@
       for (_i = 0, _len = _ref2.length; _i < _len; _i++) {
         obj = _ref2[_i];
         if (obj instanceof Assign) {
-          names.push(obj.value.unwrap().value);
+          names.push.apply(names, this.names(obj.value.unwrap()));
         } else if (obj instanceof Splat) {
           names.push(obj.name.unwrap().value);
         } else if (obj instanceof Value) {

src/nodes.coffee

@@ -1128,7 +1128,7 @@ exports.Assign = class Assign extends Base
   compileConditional: (o) ->
     [left, right] = @variable.cacheReference o
     # Disallow conditional assignment of undefined variables.
-    if not left.properties.length and left.base instanceof Literal and 
+    if not left.properties.length and left.base instanceof Literal and
            left.base.value != "this" and not o.scope.check left.base.value
       throw new Error "the variable \"#{left.base.value}\" can't be assigned with #{@context} because it has not been defined."
     if "?" in @context then o.isExistentialEquals = true
@@ -1289,7 +1289,7 @@ exports.Param = class Param extends Base
     for obj in name.objects
       # * assignments within destructured parameters `{foo:bar}`
       if obj instanceof Assign
-        names.push obj.value.unwrap().value
+        names.push @names(obj.value.unwrap())...
       # * splats within destructured parameters `[xs...]`
       else if obj instanceof Splat
         names.push obj.name.unwrap().value

test/functions.coffee

@@ -199,10 +199,17 @@ test "#2258: allow whitespace-style parameter lists in function definitions", ->
     a, b, c
   ) -> c
   eq func(1, 2, 3), 3
-  
+
   func = (
     a
     b
     c
   ) -> b
-  eq func(1, 2, 3), 2
+  eq func(1, 2, 3), 2
+
+test "#2621: fancy destructuring in parameter lists", ->
+  func = ({ prop1: { key1 }, prop2: { key2, key3: [a, b, c] } }) ->
+    eq(key2, 'key2')
+    eq(a, 'a')
+
+  func({prop1: {key1: 'key1'}, prop2: {key2: 'key2', key3: ['a', 'b', 'c']}})