Trade: make AnimationData::release() consistent with MeshData.

src/Magnum/Trade/AnimationData.cpp

@@ -100,6 +100,11 @@ const Animation::TrackViewStorage<Float>& AnimationData::mutableTrack(UnsignedIn
     return reinterpret_cast<const Animation::TrackViewStorage<Float>&>(_tracks[id]._view);
 }
 
+Containers::Array<char> AnimationData::release() {
+    _tracks = nullptr;
+    return std::move(_data);
+}
+
 template<class V, class R> auto animationInterpolatorFor(Animation::Interpolation interpolation) -> R(*)(const V&, const V&, Float) {
     return Animation::interpolatorFor<V, R>(interpolation);
 }

src/Magnum/Trade/AnimationData.h

@@ -522,12 +522,13 @@ class MAGNUM_TRADE_EXPORT AnimationData {
          * @brief Release data storage
          *
          * Releases the ownership of the data array and resets internal state
-         * to default. Note that the returned array has a custom no-op deleter
-         * when the data are not owned by the animation, and while the returned
-         * array type is mutable, the actual memory might be not.
+         * to default. The animation then behaves like it's empty. Note that
+         * the returned array has a custom no-op deleter when the data are not
+         * owned by the animation, and while the returned array type is
+         * mutable, the actual memory might be not.
          * @see @ref data(), @ref dataFlags()
          */
-        Containers::Array<char> release() { return std::move(_data); }
+        Containers::Array<char> release();
 
         /**
          * @brief Importer-specific state

src/Magnum/Trade/Test/AnimationDataTest.cpp

@@ -55,6 +55,8 @@ struct AnimationDataTest: TestSuite::Tester {
     void trackWrongType();
     void trackWrongResultType();
 
+    void release();
+
     void debugAnimationTrackType();
     void debugAnimationTrackTargetType();
 };
@@ -91,6 +93,8 @@ AnimationDataTest::AnimationDataTest() {
               &AnimationDataTest::trackWrongType,
               &AnimationDataTest::trackWrongResultType,
 
+              &AnimationDataTest::release,
+
               &AnimationDataTest::debugAnimationTrackType,
               &AnimationDataTest::debugAnimationTrackTargetType});
 }
@@ -566,6 +570,25 @@ void AnimationDataTest::trackWrongResultType() {
     CORRADE_COMPARE(out.str(), "Trade::AnimationData::track(): improper result type requested for Trade::AnimationTrackType::Vector3\n");
 }
 
+void AnimationDataTest::release() {
+    const std::pair<Float, bool> keyframes[] {
+        {1.0f, true},
+        {5.0f, false}
+    };
+
+    AnimationData data{{}, keyframes, Containers::Array<AnimationTrackData>{Containers::InPlaceInit, {
+        {AnimationTrackType::Bool,
+         AnimationTrackTargetType(129), 0,
+         Animation::TrackView<const Float, const bool>{keyframes, Animation::Interpolation::Constant}},
+        }}};
+    CORRADE_COMPARE(data.trackCount(), 1);
+
+    Containers::Array<char> released = data.release();
+    CORRADE_COMPARE(data.data(), nullptr);
+    CORRADE_COMPARE(data.trackCount(), 0);
+    CORRADE_COMPARE(static_cast<const void*>(released.data()), keyframes);
+}
+
 void AnimationDataTest::debugAnimationTrackType() {
     std::ostringstream out;