Fix crash at exit when there is a log after the Logger has been destroyed

Use a proper static Logger instead of allocating one,  and cleanup
the QTMessageLogger when it is destroyed

1 files changed, 12 insertions, 21 deletions

diff --git a/src/mirall/logger.cpp b/src/mirall/logger.cpp
index 6c8561908..0bc8d1ccb 100644
--- a/src/mirall/logger.cpp
+++ b/src/mirall/logger.cpp
@@ -27,6 +27,9 @@ static void mirallLogCatcher(QtMsgType type, const char *msg)
   // qDebug() exports to local8Bit, which is not always UTF-8
   Logger::instance()->mirallLog( QString::fromLocal8Bit(msg) );
 }
+static void qInstallMessageHandler(QtMsgHandler h) {
+    qInstallMsgHandler(h);
+}
 #else
 static void mirallLogCatcher(QtMsgType, const QMessageLogContext &ctx, const QString &message) {
     Q_UNUSED(ctx);
@@ -38,35 +41,23 @@ static void mirallLogCatcher(QtMsgType, const QMessageLogContext &ctx, const QSt
 }
 #endif
 
-Logger* Logger::_instance=0;
-
-Logger::Logger( QObject* parent)
-: QObject(parent),
-  _showTime(true), _doLogging(false), _doFileFlush(false), _logExpire(0)
+Logger *Logger::instance()
 {
+    static Logger log;
+    return &log;
 }
 
-Logger *Logger::instance()
+Logger::Logger( QObject* parent) : QObject(parent),
+  _showTime(true), _doLogging(false), _doFileFlush(false), _logExpire(0)
 {
-    if( !Logger::_instance ) {
-        Logger::_instance = new Logger;
-#if QT_VERSION < QT_VERSION_CHECK(5, 0, 0)
-        qInstallMsgHandler( mirallLogCatcher );
-#else
-        qInstallMessageHandler(mirallLogCatcher);
-#endif
-    }
-    return Logger::_instance;
+    qInstallMessageHandler(mirallLogCatcher);
 }
 
-void Logger::destroy()
-{
-    if( Logger::_instance ) {
-        delete Logger::_instance;
-        Logger::_instance = 0;
-    }
+Logger::~Logger() {
+    qInstallMessageHandler(0);
 }
 
+
 void Logger::postGuiLog(const QString &title, const QString &message)
 {
     emit guiLog(title, message);