From aa8c805b8e7faa4d60d3698ddc24e99bce84b8cd Mon Sep 17 00:00:00 2001
From: Michal Moravec <michi.m@gmail.com>
Date: Fri, 18 Sep 2015 13:31:01 +0200
Subject: [PATCH] Implemented less/less.js#2646

---
 lib/ILess/Node/MixinDefinitionNode.php        | 26 +++++++++++++++----
 .../_fixtures/less.js/css/mixins-args.css     |  3 +++
 .../_fixtures/less.js/less/mixins-args.less   | 13 ++++++++++
 3 files changed, 37 insertions(+), 5 deletions(-)

diff --git a/lib/ILess/Node/MixinDefinitionNode.php b/lib/ILess/Node/MixinDefinitionNode.php
index 5df547a..37ef94e 100644
--- a/lib/ILess/Node/MixinDefinitionNode.php
+++ b/lib/ILess/Node/MixinDefinitionNode.php
@@ -102,6 +102,11 @@ class MixinDefinitionNode extends RulesetNode
      */
     public $compileFirst = true;
 
+    /**
+     * @var array
+     */
+    protected $optionalParameters = [];
+
     /**
      * Constructor
      *
@@ -118,7 +123,8 @@ public function __construct(
         $condition = null,
         $variadic = false,
         $frames = []
-    ) {
+    )
+    {
         $this->name = $name;
         $this->selectors = [new SelectorNode([new ElementNode(null, $name)])];
 
@@ -133,6 +139,8 @@ public function __construct(
             foreach ($params as $p) {
                 if (!isset($p['name']) || ($p['name'] && !isset($p['value']))) {
                     $this->required++;
+                } else {
+                    $this->optionalParameters[] = $p['name'];
                 }
             }
         }
@@ -219,7 +227,8 @@ public function compileParams(
         Context $mixinEnv,
         $arguments = [],
         array &$compiledArguments = []
-    ) {
+    )
+    {
         $frame = new RulesetNode([], []);
         $params = $this->params;
         $argsCount = 0;
@@ -350,20 +359,27 @@ public function matchArgs(array $args, Context $context)
     {
         $argsLength = count($args);
 
+        $requiredArgsCount = 0;
+        foreach ($args as $arg) {
+            if (!isset($arg['name']) || !in_array($arg['name'], $this->optionalParameters)) {
+                $requiredArgsCount++;
+            }
+        }
+
         if (!$this->variadic) {
-            if ($argsLength < $this->required) {
+            if ($requiredArgsCount < $this->required) {
                 return false;
             }
             if ($argsLength > count($this->params)) {
                 return false;
             }
         } else {
-            if ($argsLength < ($this->required - 1)) {
+            if ($requiredArgsCount < ($this->required - 1)) {
                 return false;
             }
         }
 
-        $len = min($argsLength, $this->arity);
+        $len = min($requiredArgsCount, $this->arity);
 
         for ($i = 0; $i < $len; $i++) {
             if (!isset($this->params[$i]['name']) && !isset($this->params[$i]['variadic'])) {
diff --git a/tests/ILess/Test/Parser/_fixtures/less.js/css/mixins-args.css b/tests/ILess/Test/Parser/_fixtures/less.js/css/mixins-args.css
index 07df8b1..c97232b 100644
--- a/tests/ILess/Test/Parser/_fixtures/less.js/css/mixins-args.css
+++ b/tests/ILess/Test/Parser/_fixtures/less.js/css/mixins-args.css
@@ -158,3 +158,6 @@ mixins-args-expand-op-9 {
   a4: and;
   a8: 5;
 }
+#test-mixin-matching-when-default-2645 {
+  height: 20px;
+}
diff --git a/tests/ILess/Test/Parser/_fixtures/less.js/less/mixins-args.less b/tests/ILess/Test/Parser/_fixtures/less.js/less/mixins-args.less
index 12b55c1..57f5a5b 100644
--- a/tests/ILess/Test/Parser/_fixtures/less.js/less/mixins-args.less
+++ b/tests/ILess/Test/Parser/_fixtures/less.js/less/mixins-args.less
@@ -248,3 +248,16 @@ mixins-args-expand-op- {
     a8: extract(@a, 8);
   }
 }
+#test-mixin-matching-when-default-2645 {
+  .mixin(@height) {
+    height: @height;
+  }
+
+  .mixin(@width, @height: 10px) {
+    width: @width;
+
+    .mixin(@height: @height);
+  }
+
+  .mixin(@height: 20px);
+}
\ No newline at end of file