From abd663ee59a5e91130ccfd64aa82c08e14f4d3aa Mon Sep 17 00:00:00 2001
From: Javier Eguiluz <javier.eguiluz@gmail.com>
Date: Sun, 2 Aug 2015 13:28:24 +0200
Subject: [PATCH 1/3] Allow to define Enum nodes with 1 single element

---
 src/Symfony/Component/Config/Definition/EnumNode.php |  7 +------
 .../Config/Tests/Definition/EnumNodeTest.php         | 12 ++++++++----
 2 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/src/Symfony/Component/Config/Definition/EnumNode.php b/src/Symfony/Component/Config/Definition/EnumNode.php
index 224871ab6fe02..3730f0fdadfab 100644
--- a/src/Symfony/Component/Config/Definition/EnumNode.php
+++ b/src/Symfony/Component/Config/Definition/EnumNode.php
@@ -24,13 +24,8 @@ class EnumNode extends ScalarNode
 
     public function __construct($name, NodeInterface $parent = null, array $values = array())
     {
-        $values = array_unique($values);
-        if (count($values) <= 1) {
-            throw new \InvalidArgumentException('$values must contain at least two distinct elements.');
-        }
-
         parent::__construct($name, $parent);
-        $this->values = $values;
+        $this->values = array_unique($values);
     }
 
     public function getValues()
diff --git a/src/Symfony/Component/Config/Tests/Definition/EnumNodeTest.php b/src/Symfony/Component/Config/Tests/Definition/EnumNodeTest.php
index 2b84de6b098f7..34a3b727fcd83 100644
--- a/src/Symfony/Component/Config/Tests/Definition/EnumNodeTest.php
+++ b/src/Symfony/Component/Config/Tests/Definition/EnumNodeTest.php
@@ -21,12 +21,16 @@ public function testFinalizeValue()
         $this->assertSame('foo', $node->finalize('foo'));
     }
 
-    /**
-     * @expectedException \InvalidArgumentException
-     */
     public function testConstructionWithOneValue()
     {
-        new EnumNode('foo', null, array('foo', 'foo'));
+        $node = new EnumNode('foo', null, array('foo'));
+        $this->assertSame('foo', $node->finalize('foo'));
+    }
+
+    public function testConstructionWithOneDistinctValue()
+    {
+        $node = new EnumNode('foo', null, array('foo', 'foo'));
+        $this->assertSame('foo', $node->finalize('foo'));
     }
 
     /**

From e75a983c42178caf11a99556bf1063fb5e605db8 Mon Sep 17 00:00:00 2001
From: Javier Eguiluz <javier.eguiluz@gmail.com>
Date: Sun, 2 Aug 2015 16:35:20 +0200
Subject: [PATCH 2/3] Prevent empty arrays for Enum nodes

---
 src/Symfony/Component/Config/Definition/EnumNode.php     | 7 ++++++-
 .../Component/Config/Tests/Definition/EnumNodeTest.php   | 9 +++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/src/Symfony/Component/Config/Definition/EnumNode.php b/src/Symfony/Component/Config/Definition/EnumNode.php
index 3730f0fdadfab..9b4c4156e311e 100644
--- a/src/Symfony/Component/Config/Definition/EnumNode.php
+++ b/src/Symfony/Component/Config/Definition/EnumNode.php
@@ -24,8 +24,13 @@ class EnumNode extends ScalarNode
 
     public function __construct($name, NodeInterface $parent = null, array $values = array())
     {
+        $values = array_unique($values);
+        if (empty($values)) {
+            throw new \InvalidArgumentException('$values must contain at least one element.');
+        }
+
         parent::__construct($name, $parent);
-        $this->values = array_unique($values);
+        $this->values = $values;
     }
 
     public function getValues()
diff --git a/src/Symfony/Component/Config/Tests/Definition/EnumNodeTest.php b/src/Symfony/Component/Config/Tests/Definition/EnumNodeTest.php
index 34a3b727fcd83..654d5050dd9c9 100644
--- a/src/Symfony/Component/Config/Tests/Definition/EnumNodeTest.php
+++ b/src/Symfony/Component/Config/Tests/Definition/EnumNodeTest.php
@@ -21,6 +21,15 @@ public function testFinalizeValue()
         $this->assertSame('foo', $node->finalize('foo'));
     }
 
+    /**
+     * @expectedException \InvalidArgumentException
+     * @expectedExceptionMessage $values must contain at least one element.
+     */
+    public function testConstructionWithNoValues()
+    {
+        new EnumNode('foo', null, array());
+    }
+
     public function testConstructionWithOneValue()
     {
         $node = new EnumNode('foo', null, array('foo'));

From c12fbba15082231fd5c98d9855f685ad28cc9597 Mon Sep 17 00:00:00 2001
From: Javier Eguiluz <javier.eguiluz@gmail.com>
Date: Mon, 3 Aug 2015 10:23:17 +0200
Subject: [PATCH 3/3] Added a note about the BC break in Enum config nodes

---
 UPGRADE-2.8.md | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/UPGRADE-2.8.md b/UPGRADE-2.8.md
index 2c18e58f50a5e..655acee0de431 100644
--- a/UPGRADE-2.8.md
+++ b/UPGRADE-2.8.md
@@ -399,3 +399,23 @@ FrameworkBundle
        session:
            cookie_httponly: false
    ```
+
+Config
+------
+
+The edge case of defining just one value for nodes of type Enum is now allowed:
+
+```php
+$rootNode
+    ->children()
+        ->enumNode('variable')
+            ->values(array('value'))
+        ->end()
+    ->end()
+;
+```
+
+Before: `InvalidArgumentException` (variable must contain at least two
+distinct elements).
+After: the code will work as expected and it will restrict the values of the
+`variable` option to just `value`.