LibAudio: Make LoaderPlugin::error_string return String&

Previously, error_string() returned char* which is bad Serenity style
and caused issues when other error handling methods were tried. As both
WavLoader and (future) FLAC loader store a String internally for the
error message, it makes sense to return a String reference instead.

2 files changed, 6 insertions, 3 deletions

diff --git a/Userland/Libraries/LibAudio/Loader.h b/Userland/Libraries/LibAudio/Loader.h
index 5075b0062a..a4bad829c1 100644
--- a/Userland/Libraries/LibAudio/Loader.h
+++ b/Userland/Libraries/LibAudio/Loader.h
@@ -15,6 +15,9 @@
 
 namespace Audio {
 
+static const String empty_string = "";
+static String no_plugin_error = "No loader plugin available";
+
 class LoaderPlugin {
 public:
     virtual ~LoaderPlugin() { }
@@ -22,7 +25,7 @@ public:
     virtual bool sniff() = 0;
 
     virtual bool has_error() { return false; }
-    virtual const char* error_string() { return ""; }
+    virtual const String& error_string() { return empty_string; }
 
     virtual RefPtr<Buffer> get_more_samples(size_t max_bytes_to_read_from_input = 128 * KiB) = 0;
 
@@ -52,7 +55,7 @@ public:
     static NonnullRefPtr<Loader> create(const ByteBuffer& buffer) { return adopt_ref(*new Loader(buffer)); }
 
     bool has_error() const { return m_plugin ? m_plugin->has_error() : true; }
-    const char* error_string() const { return m_plugin ? m_plugin->error_string() : "No loader plugin available"; }
+    const String& error_string() const { return m_plugin ? m_plugin->error_string() : no_plugin_error; }
 
     RefPtr<Buffer> get_more_samples(size_t max_bytes_to_read_from_input = 128 * KiB) const { return m_plugin ? m_plugin->get_more_samples(max_bytes_to_read_from_input) : nullptr; }
 
diff --git a/Userland/Libraries/LibAudio/WavLoader.h b/Userland/Libraries/LibAudio/WavLoader.h
index db333b571f..4eaa4b9a4b 100644
--- a/Userland/Libraries/LibAudio/WavLoader.h
+++ b/Userland/Libraries/LibAudio/WavLoader.h
@@ -39,7 +39,7 @@ public:
     virtual bool sniff() override { return valid; }
 
     virtual bool has_error() override { return !m_error_string.is_null(); }
-    virtual const char* error_string() override { return m_error_string.characters(); }
+    virtual const String& error_string() override { return m_error_string; }
 
     // The Buffer returned contains input data resampled at the
     // destination audio device sample rate.