GCC 4.5 compatibility: nullptr-related issues.

src/Audio/Test/AbstractImporterTest.cpp

@@ -59,7 +59,13 @@ void AbstractImporterTest::openFile() {
 
             Buffer::Format doFormat() const override { return Buffer::Format(); }
             UnsignedInt doFrequency() const override { return {}; }
-            Corrade::Containers::Array<unsigned char> doData() override { return nullptr; }
+            Corrade::Containers::Array<unsigned char> doData() override {
+                #ifndef CORRADE_GCC45_COMPATIBILITY
+                return nullptr;
+                #else
+                return {};
+                #endif
+            }
 
             bool opened;
     };