Revert "Initialize QLoggingRegistry rules on first use, not qApp construction"

This reverts commit 47cc9e23a313d67a4a3107242f205d2473842021.

We use QCoreApplication::applicationDirPath in the logging initialization to find
a possible qtlogging.ini file. Because QCoreApplication::applicationDirPath requires
a QCoreApplication instance this leads to a qWarning, which in turn leads to a
recursive call to the logging initialization, and in turn to a recursive mutex deadlock.

Task-number: QTCREATORBUG-18031
Change-Id: Ic75e1e8c062eb647991725378489bf87c9648cca
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>

4 files changed, 6 insertions, 18 deletions

diff --git a/src/corelib/io/qloggingregistry.cpp b/src/corelib/io/qloggingregistry.cpp
index 9a5c923323..47fb1fb6b8 100644
--- a/src/corelib/io/qloggingregistry.cpp
+++ b/src/corelib/io/qloggingregistry.cpp
@@ -255,7 +255,6 @@ void QLoggingSettingsParser::parseNextLine(QStringRef line)
 QLoggingRegistry::QLoggingRegistry()
     : categoryFilter(defaultCategoryFilter)
 {
-    init();
 }
 
 static bool qtLoggingDebug()
diff --git a/src/corelib/io/qloggingregistry_p.h b/src/corelib/io/qloggingregistry_p.h
index 768f3b4a91..69fc6ea4ec 100644
--- a/src/corelib/io/qloggingregistry_p.h
+++ b/src/corelib/io/qloggingregistry_p.h
@@ -113,6 +113,8 @@ class Q_AUTOTEST_EXPORT QLoggingRegistry
 public:
     QLoggingRegistry();
 
+    void init();
+
     void registerCategory(QLoggingCategory *category, QtMsgType enableForLevel);
     void unregisterCategory(QLoggingCategory *category);
 
@@ -124,7 +126,6 @@ public:
     static QLoggingRegistry *instance();
 
 private:
-    void init();
     void updateRules();
 
     static void defaultCategoryFilter(QLoggingCategory *category);
diff --git a/src/corelib/kernel/qcoreapplication.cpp b/src/corelib/kernel/qcoreapplication.cpp
index 0216baa6c3..e4b1562b8b 100644
--- a/src/corelib/kernel/qcoreapplication.cpp
+++ b/src/corelib/kernel/qcoreapplication.cpp
@@ -771,6 +771,8 @@ void QCoreApplicationPrivate::init()
     if (!coreappdata()->applicationVersionSet)
         coreappdata()->applicationVersion = appVersion();
 
+    QLoggingRegistry::instance()->init();
+
 #if QT_CONFIG(library)
     // Reset the lib paths, so that they will be recomputed, taking the availability of argv[0]
     // into account. If necessary, recompute right away and replay the manual changes on top of the
diff --git a/tests/auto/corelib/io/qloggingregistry/tst_qloggingregistry.cpp b/tests/auto/corelib/io/qloggingregistry/tst_qloggingregistry.cpp
index c697cb2203..0a74dc64c0 100644
--- a/tests/auto/corelib/io/qloggingregistry/tst_qloggingregistry.cpp
+++ b/tests/auto/corelib/io/qloggingregistry/tst_qloggingregistry.cpp
@@ -197,23 +197,9 @@ private slots:
         // Check whether QT_LOGGING_CONF is picked up from environment
         //
 
-        Q_ASSERT(!qApp);
-
-        qputenv("QT_LOGGING_RULES", "qt.foo.bar=true");
+        qputenv("QT_LOGGING_CONF", QFINDTESTDATA("qtlogging.ini").toLocal8Bit());
 
         QLoggingRegistry registry;
-        QCOMPARE(registry.apiRules.size(), 0);
-        QCOMPARE(registry.configRules.size(), 0);
-        QCOMPARE(registry.envRules.size(), 1);
-        QCOMPARE(registry.rules.size(), 1);
-
-        QLoggingCategory qtEnabledByLoggingRule("qt.foo.bar");
-        QCOMPARE(qtEnabledByLoggingRule.isDebugEnabled(), true);
-        QLoggingCategory qtDisabledByDefault("qt.foo.baz");
-        QCOMPARE(qtDisabledByDefault.isDebugEnabled(), false);
-
-        qunsetenv("QT_LOGGING_RULES");
-        qputenv("QT_LOGGING_CONF", QFINDTESTDATA("qtlogging.ini").toLocal8Bit());
         registry.init();
 
         QCOMPARE(registry.apiRules.size(), 0);
@@ -318,6 +304,6 @@ private slots:
     }
 };
 
-QTEST_APPLESS_MAIN(tst_QLoggingRegistry)
+QTEST_MAIN(tst_QLoggingRegistry)
 
 #include "tst_qloggingregistry.moc"