Fixed awesome bug in Vector3 constructor.

Updated unit test to make sure it won't happen again.

src/Math/Test/Vector2Test.cpp

@@ -29,6 +29,10 @@ namespace Magnum { namespace Math { namespace Test {
 
 typedef Math::Vector2<float> Vector2;
 
+void Vector2Test::construct() {
+    QVERIFY((Vector2(1, 2) == Vector<float, 2>(1.0f, 2.0f)));
+}
+
 void Vector2Test::debug() {
     ostringstream o;
     Debug(&o) << Vector2(0.5f, 15.0f);

src/Math/Test/Vector2Test.h

@@ -23,6 +23,7 @@ class Vector2Test: public QObject {
     Q_OBJECT
 
     private slots:
+        void construct();
         void debug();
 };
 

src/Math/Test/Vector3Test.cpp

@@ -29,6 +29,11 @@ namespace Magnum { namespace Math { namespace Test {
 
 typedef Math::Vector3<float> Vector3;
 
+void Vector3Test::construct() {
+    QVERIFY((Vector3(1, 2, 3) == Vector<float, 3>(1.0f, 2.0f, 3.0f)));
+    QVERIFY((Vector3(Vector<float, 2>(1.0f, 2.0f), 3) == Vector<float, 3>(1.0f, 2.0f, 3.0f)));
+}
+
 void Vector3Test::cross() {
     Vector3 a(1, -1, 1);
     Vector3 b(4, 3, 7);

src/Math/Test/Vector3Test.h

@@ -23,6 +23,7 @@ class Vector3Test: public QObject {
     Q_OBJECT
 
     private slots:
+        void construct();
         void cross();
 
         void debug();

src/Math/Test/Vector4Test.cpp

@@ -32,6 +32,8 @@ typedef Math::Vector3<float> Vector3;
 
 void Vector4Test::construct() {
     QVERIFY(Vector4() == Vector4(0.0f, 0.0f, 0.0f, 1.0f));
+    QVERIFY((Vector4(1, 2, 3, 4) == Vector<float, 4>(1.0f, 2.0f, 3.0f, 4.0f)));
+    QVERIFY((Vector4(Vector<float, 3>(1.0f, 2.0f, 3.0f), 4) == Vector<float, 4>(1.0f, 2.0f, 3.0f, 4.0f)));
 }
 
 void Vector4Test::threeComponent() {

src/Math/Vector3.h

@@ -64,7 +64,7 @@ template<class T> class Vector3: public Vector<T, 3> {
          * @param other     Two component vector
          * @param z         Z / B value
          */
-        inline Vector3(const Vector<T, 2>& other, T z = T(0)): Vector<T, 3>(other[0], other[1], other[2]) {}
+        inline Vector3(const Vector<T, 2>& other, T z = T(0)): Vector<T, 3>(other[0], other[1], z) {}
 
         inline T x() const { return Vector<T, 3>::at(0); } /**< @brief X component */
         inline T y() const { return Vector<T, 3>::at(1); } /**< @brief Y component */