WavAudioImporter: a file with zero samples is not an error.

src/MagnumPlugins/WavAudioImporter/Test/CMakeLists.txt

@@ -58,6 +58,8 @@ corrade_add_test(WavAudioImporterTest WavImporterTest.cpp
         invalidDataChunk.wav
         invalidFactChunk.wav
 
+        zeroSamples.wav
+
         mono4.wav
         mono8.wav
         mono8junk.wav

src/MagnumPlugins/WavAudioImporter/Test/WavImporterTest.cpp

@@ -50,6 +50,8 @@ struct WavImporterTest: TestSuite::Tester {
     void invalidDataChunk();
     void invalidFactChunk();
 
+    void zeroSamples();
+
     void mono4();
     void mono8();
     void mono8junk();
@@ -88,6 +90,8 @@ WavImporterTest::WavImporterTest() {
               &WavImporterTest::invalidDataChunk,
               &WavImporterTest::invalidFactChunk,
 
+              &WavImporterTest::zeroSamples,
+
               &WavImporterTest::mono4,
               &WavImporterTest::mono8,
               &WavImporterTest::mono8junk,
@@ -195,6 +199,16 @@ void WavImporterTest::invalidFactChunk() {
         TestSuite::Compare::Container<Containers::ArrayView<const char>>);
 }
 
+void WavImporterTest::zeroSamples() {
+    Containers::Pointer<AbstractImporter> importer = _manager.instantiate("WavAudioImporter");
+
+    /* No error should happen, it should just give an empty buffer back */
+    CORRADE_VERIFY(importer->openFile(Utility::Directory::join(WAVAUDIOIMPORTER_TEST_DIR, "zeroSamples.wav")));
+    CORRADE_COMPARE(importer->format(), BufferFormat::Mono16);
+    CORRADE_COMPARE(importer->frequency(), 22050);
+    CORRADE_VERIFY(importer->data().empty());
+}
+
 void WavImporterTest::mono4() {
     std::ostringstream out;
     Error redirectError{&out};

src/MagnumPlugins/WavAudioImporter/WavImporter.cpp

@@ -45,7 +45,7 @@ WavImporter::WavImporter(PluginManager::AbstractManager& manager, const std::str
 
 auto WavImporter::doFeatures() const -> Features { return Feature::OpenData; }
 
-bool WavImporter::doIsOpened() const { return _data; }
+bool WavImporter::doIsOpened() const { return !!_data; }
 
 void WavImporter::doOpenData(Containers::ArrayView<const char> data) {
     /* Check file size */
@@ -213,19 +213,19 @@ void WavImporter::doOpenData(Containers::ArrayView<const char> data) {
     /* Copy the data */
     const char* dataChunkPtr = reinterpret_cast<const char*>(dataChunk + 1);
     _data = Containers::Array<char>(dataChunkSize);
-    std::copy(dataChunkPtr, dataChunkPtr+dataChunkSize, _data.begin());
+    std::copy(dataChunkPtr, dataChunkPtr+dataChunkSize, _data->begin());
     return;
 }
 
-void WavImporter::doClose() { _data = nullptr; }
+void WavImporter::doClose() { _data = Containers::NullOpt; }
 
 BufferFormat WavImporter::doFormat() const { return _format; }
 
 UnsignedInt WavImporter::doFrequency() const { return _frequency; }
 
 Containers::Array<char> WavImporter::doData() {
-    Containers::Array<char> copy(_data.size());
-    std::copy(_data.begin(), _data.end(), copy.begin());
+    Containers::Array<char> copy(_data->size());
+    std::copy(_data->begin(), _data->end(), copy.begin());
     return copy;
 }
 

src/MagnumPlugins/WavAudioImporter/WavImporter.h

@@ -31,6 +31,7 @@
  */
 
 #include <Corrade/Containers/Array.h>
+#include <Corrade/Containers/Optional.h>
 
 #include "Magnum/Audio/AbstractImporter.h"
 
@@ -102,7 +103,7 @@ class MAGNUM_WAVAUDIOIMPORTER_EXPORT WavImporter: public AbstractImporter {
         MAGNUM_WAVAUDIOIMPORTER_LOCAL UnsignedInt doFrequency() const override;
         MAGNUM_WAVAUDIOIMPORTER_LOCAL Containers::Array<char> doData() override;
 
-        Containers::Array<char> _data;
+        Containers::Optional<Containers::Array<char>> _data;
         BufferFormat _format;
         UnsignedInt _frequency;
 };