From 99b19b9539c2f132f9f22163dae4939e35eef2d1 Mon Sep 17 00:00:00 2001
From: Adriaan de Groot <groot@kde.org>
Date: Tue, 22 Mar 2022 12:54:54 +0100
Subject: [PATCH] [libcalamares] Always log to file, sometimes to terminal

---
 src/libcalamares/utils/Logger.cpp | 77 ++++++++++++++++++-------------
 1 file changed, 46 insertions(+), 31 deletions(-)

diff --git a/src/libcalamares/utils/Logger.cpp b/src/libcalamares/utils/Logger.cpp
index adb082687..10f7cad8c 100644
--- a/src/libcalamares/utils/Logger.cpp
+++ b/src/libcalamares/utils/Logger.cpp
@@ -53,7 +53,14 @@ setupLogLevel( unsigned int level )
     {
         level = LOGVERBOSE;
     }
-    s_threshold = level + 1;  // Comparison is < in log() function
+    s_threshold = level + 1;  // Comparison is < in logLevelEnabled() function
+}
+
+unsigned int
+logLevel()
+{
+    // Undo the +1 in setupLogLevel()
+    return s_threshold > 0 ? s_threshold - 1 : 0;
 }
 
 bool
@@ -62,33 +69,40 @@ logLevelEnabled( unsigned int level )
     return level < s_threshold;
 }
 
-unsigned int
-logLevel()
+/** @brief Should we call the log_implementation() function with this level?
+ *
+ * The implementation logs everything for which logLevelEnabled() is
+ * true to the file **and** to stdout; it logs everything at debug-level
+ * or below to the file regardless.
+ */
+static inline bool
+log_enabled( unsigned int level )
 {
-    return s_threshold > 0 ? s_threshold - 1 : 0;
+    return level <= LOGDEBUG || logLevelEnabled( level );
 }
 
 static void
-log( const char* msg, unsigned int debugLevel, bool withTime = true )
+log_implementation( const char* msg, unsigned int debugLevel, const bool withTime )
 {
+    QMutexLocker lock( &s_mutex );
+
+    const auto date = QDate::currentDate().toString( Qt::ISODate );
+    const auto time = QTime::currentTime().toString();
+
+    // If we don't format the date as a Qt::ISODate then we get a crash when
+    // logging at exit as Qt tries to use QLocale to format, but QLocale is
+    // on its way out.
+    logfile << date.toUtf8().data() << " - " << time.toUtf8().data() << " [" << debugLevel << "]: " << msg << std::endl;
+
+    logfile.flush();
+
     if ( logLevelEnabled( debugLevel ) )
     {
-        QMutexLocker lock( &s_mutex );
-
-        // If we don't format the date as a Qt::ISODate then we get a crash when
-        // logging at exit as Qt tries to use QLocale to format, but QLocale is
-        // on its way out.
-        logfile << QDate::currentDate().toString( Qt::ISODate ).toUtf8().data() << " - "
-                << QTime::currentTime().toString().toUtf8().data() << " ["
-                << QString::number( debugLevel ).toUtf8().data() << "]: " << msg << std::endl;
-
-        logfile.flush();
-
         if ( withTime )
         {
-            std::cout << QTime::currentTime().toString().toUtf8().data() << " ["
-                      << QString::number( debugLevel ).toUtf8().data() << "]: ";
+            std::cout << time.toUtf8().data() << " [" << debugLevel << "]: ";
         }
+        // The endl is desired, since it also flushes (like the logfile, above)
         std::cout << msg << std::endl;
     }
 }
@@ -97,29 +111,30 @@ log( const char* msg, unsigned int debugLevel, bool withTime = true )
 static void
 CalamaresLogHandler( QtMsgType type, const QMessageLogContext&, const QString& msg )
 {
-    static QMutex s_mutex;
-
-    QByteArray ba = msg.toUtf8();
-    const char* message = ba.constData();
-
-    QMutexLocker locker( &s_mutex );
-
+    unsigned int level = LOGVERBOSE;
     switch ( type )
     {
     case QtInfoMsg:
-        log( message, LOGVERBOSE );
+        level = LOGVERBOSE;
         break;
     case QtDebugMsg:
-        log( message, LOGDEBUG );
+        level = LOGDEBUG;
         break;
     case QtWarningMsg:
-        log( message, LOGWARNING );
+        level = LOGWARNING;
         break;
     case QtCriticalMsg:
     case QtFatalMsg:
-        log( message, LOGERROR );
+        level = LOGERROR;
         break;
     }
+
+    if ( !log_enabled( level ) )
+    {
+        return;
+    }
+
+    log_implementation( msg.toUtf8().constData(), level, true );
 }
 
 
@@ -188,14 +203,14 @@ CDebug::CDebug( unsigned int debugLevel, const char* func )
 
 CDebug::~CDebug()
 {
-    if ( logLevelEnabled( m_debugLevel ) )
+    if ( log_enabled( m_debugLevel ) )
     {
         if ( m_funcinfo )
         {
             m_msg.prepend( s_Continuation );  // Prepending, so back-to-front
             m_msg.prepend( m_funcinfo );
         }
-        log( m_msg.toUtf8().data(), m_debugLevel, m_funcinfo );
+        log_implementation( m_msg.toUtf8().data(), m_debugLevel, bool( m_funcinfo ) );
     }
 }