9 files changed, 17 insertions, 81 deletions
diff --git a/src/corelib/kernel/qcoreapplication.cpp b/src/corelib/kernel/qcoreapplication.cpp
index 6d860bc1e7c..635c69912b1 100644
--- a/src/corelib/kernel/qcoreapplication.cpp
+++ b/src/corelib/kernel/qcoreapplication.cpp
@@ -115,10 +115,6 @@
 
 QT_BEGIN_NAMESPACE
 
-#ifndef QT_NO_QOBJECT
-Q_LOGGING_CATEGORY(lcDeleteLater, "qt.core.qobject.deletelater")
-#endif
-
 using namespace Qt::StringLiterals;
 
 Q_TRACE_PREFIX(qtcore,
@@ -1481,8 +1477,6 @@ void QCoreApplicationPrivate::execCleanup()
 {
     threadData.loadRelaxed()->quitNow = false;
     in_exec = false;
-
-    qCDebug(lcDeleteLater) << "Sending deferred delete events as part of exec cleanup";
     QCoreApplication::sendPostedEvents(nullptr, QEvent::DeferredDelete);
 }
 
@@ -1853,37 +1847,16 @@ void QCoreApplicationPrivate::sendPostedEvents(QObject *receiver, int event_type
             //    events posted by the current event loop; or
             // 3) if the event was posted before the outermost event loop.
 
-            const auto *event = static_cast<QDeferredDeleteEvent *>(pe.event);
-            qCDebug(lcDeleteLater) << "Processing deferred delete event for" << pe.receiver
-                << "with loop level" << event->loopLevel() << "and scope level" << event->scopeLevel();
-
-            qCDebug(lcDeleteLater) << "Checking" << data->thread << "with loop level"
-                << data->loopLevel << "and scope level" << data->scopeLevel;
-
-            bool allowDeferredDelete = false;
-            if (event->loopLevel() == 0 && data->loopLevel > 0) {
-                qCDebug(lcDeleteLater) << "Event was posted outside outermost event loop"
-                    << "and current thread has an event loop running.";
-                allowDeferredDelete = true;
-            } else {
-                const int totalEventLevel = event->loopLevel() + event->scopeLevel();
-                const int totalThreadLevel = data->loopLevel + data->scopeLevel;
-
-                if (totalEventLevel > totalThreadLevel) {
-                    qCDebug(lcDeleteLater) << "Combined levels of event" << totalEventLevel
-                        << "is higher than thread" << totalThreadLevel;
-                    allowDeferredDelete = true;
-                } else if (event_type == QEvent::DeferredDelete && totalEventLevel == totalThreadLevel) {
-                    qCDebug(lcDeleteLater) << "Explicit send of DeferredDelete and"
-                        << "levels of event" << totalEventLevel
-                        << "is same as thread" << totalThreadLevel;
-                    allowDeferredDelete = true;
-                }
-            }
+            const int eventLoopLevel = static_cast<QDeferredDeleteEvent *>(pe.event)->loopLevel();
+            const int eventScopeLevel = static_cast<QDeferredDeleteEvent *>(pe.event)->scopeLevel();
 
+            const bool postedBeforeOutermostLoop = eventLoopLevel == 0;
+            const bool allowDeferredDelete =
+                (eventLoopLevel + eventScopeLevel > data->loopLevel + data->scopeLevel
+                 || (postedBeforeOutermostLoop && data->loopLevel > 0)
+                 || (event_type == QEvent::DeferredDelete
+                     && eventLoopLevel + eventScopeLevel == data->loopLevel + data->scopeLevel));
             if (!allowDeferredDelete) {
-                qCDebug(lcDeleteLater) << "Failed conditions for deferred delete. Deferring again";
-
                 // cannot send deferred delete
                 if (!event_type && !receiver) {
                     // we must copy it first; we want to re-post the event
@@ -1900,8 +1873,6 @@ void QCoreApplicationPrivate::sendPostedEvents(QObject *receiver, int event_type
                     data->postEventList.addEvent(pe_copy);
                 }
                 continue;
-            } else {
-                qCDebug(lcDeleteLater) << "Sending deferred delete to" << pe.receiver;
             }
         }
 
diff --git a/src/corelib/kernel/qcoreapplication_p.h b/src/corelib/kernel/qcoreapplication_p.h
index a1e0e4d560a..ed18df4e72f 100644
--- a/src/corelib/kernel/qcoreapplication_p.h
+++ b/src/corelib/kernel/qcoreapplication_p.h
@@ -25,7 +25,6 @@
 #include "QtCore/qsettings.h"
 #endif
 #ifndef QT_NO_QOBJECT
-#include <qloggingcategory.h>
 #include "private/qobject_p.h"
 #include "private/qlocking_p.h"
 #endif
@@ -36,10 +35,6 @@
 
 QT_BEGIN_NAMESPACE
 
-#ifndef QT_NO_QOBJECT
-Q_DECLARE_LOGGING_CATEGORY(lcDeleteLater)
-#endif
-
 typedef QList<QTranslator*> QTranslatorList;
 
 class QAbstractEventDispatcher;
diff --git a/src/corelib/kernel/qeventloop.cpp b/src/corelib/kernel/qeventloop.cpp
index 500b67ea6ae..c02afd172dc 100644
--- a/src/corelib/kernel/qeventloop.cpp
+++ b/src/corelib/kernel/qeventloop.cpp
@@ -155,9 +155,6 @@ int QEventLoop::exec(ProcessEventsFlags flags)
             auto threadData = d->threadData.loadRelaxed();
             ++threadData->loopLevel;
             threadData->eventLoops.push(d->q_func());
-            qCDebug(lcDeleteLater) << "Increased" << threadData->thread
-                      << "loop level to" << threadData->loopLevel
-                      << "with leaf loop now" << threadData->eventLoops.last();
 
             locker.unlock();
         }
@@ -176,12 +173,6 @@ int QEventLoop::exec(ProcessEventsFlags flags)
             Q_UNUSED(eventLoop); // --release warning
             d->inExec = false;
             --threadData->loopLevel;
-
-            qCDebug(lcDeleteLater) << "Decreased" << threadData->thread
-                      << "loop level to" << threadData->loopLevel
-                      << "with leaf loop now" << (threadData->eventLoops.isEmpty()
-                        ? nullptr : threadData->eventLoops.last());
-
         }
     };
     LoopReference ref(d, locker);
diff --git a/src/corelib/kernel/qobject.cpp b/src/corelib/kernel/qobject.cpp
index 7c179c4bde5..2a419aabf8e 100644
--- a/src/corelib/kernel/qobject.cpp
+++ b/src/corelib/kernel/qobject.cpp
@@ -1413,7 +1413,6 @@ bool QObject::event(QEvent *e)
         break;
 
     case QEvent::DeferredDelete:
-        qCDebug(lcDeleteLater) << "Deferred deleting" << this;
         delete this;
         break;
 
@@ -2464,10 +2463,8 @@ void QObject::deleteLater()
     // as long as we're not guarding every access to the bit field.
 
     Q_D(QObject);
-    if (d->deleteLaterCalled) {
-        qCDebug(lcDeleteLater) << "Skipping deleteLater for already deferred object" << this;
+    if (d->deleteLaterCalled)
         return;
-    }
 
     d->deleteLaterCalled = true;
 
@@ -2493,16 +2490,10 @@ void QObject::deleteLater()
         // non-conformant code path, and our best guess is that the scope level
         // should be 1. (Loop level 0 is special: it means that no event loops
         // are running.)
-        if (scopeLevel == 0 && loopLevel != 0) {
-            qCDebug(lcDeleteLater) << "Delete later called with scope level 0"
-                << "but loop level is > 0. Assuming scope is 1";
+        if (scopeLevel == 0 && loopLevel != 0)
             scopeLevel = 1;
-        }
     }
 
-    qCDebug(lcDeleteLater) << "Posting deferred delete for" << this
-        << "with loop level" << loopLevel << "and scope level" << scopeLevel;
-
     eventListLocker.unlock();
     QCoreApplication::postEvent(this,
         new QDeferredDeleteEvent(loopLevel, scopeLevel));
diff --git a/src/corelib/kernel/qtranslator.cpp b/src/corelib/kernel/qtranslator.cpp
index f3846e38c23..713c029c347 100644
--- a/src/corelib/kernel/qtranslator.cpp
+++ b/src/corelib/kernel/qtranslator.cpp
@@ -19,6 +19,7 @@
 #include "qtranslator_p.h"
 #include "qlocale.h"
 #include "qlogging.h"
+#include "qloggingcategory.h"
 #include "qdebug.h"
 #include "qendian.h"
 #include "qresource.h"
diff --git a/src/corelib/thread/qthread.cpp b/src/corelib/thread/qthread.cpp
index 08e8368043e..b5b4618e0bd 100644
--- a/src/corelib/thread/qthread.cpp
+++ b/src/corelib/thread/qthread.cpp
@@ -131,21 +131,6 @@ void QAdoptedThread::run()
 }
 #endif
 
-QScopedScopeLevelCounter::QScopedScopeLevelCounter(QThreadData *threadData)
-    : threadData(threadData)
-{
-    ++threadData->scopeLevel;
-    qCDebug(lcDeleteLater) << "Increased" << threadData->thread
-                      << "scope level to" << threadData->scopeLevel;
-}
-
-QScopedScopeLevelCounter::~QScopedScopeLevelCounter()
-{
-    --threadData->scopeLevel;
-    qCDebug(lcDeleteLater) << "Decreased" << threadData->thread
-                      << "scope level to" << threadData->scopeLevel;
-}
-
 #if QT_CONFIG(thread)
 /*
   QThreadPrivate
diff --git a/src/corelib/thread/qthread_p.h b/src/corelib/thread/qthread_p.h
index eb721509776..547c2867f16 100644
--- a/src/corelib/thread/qthread_p.h
+++ b/src/corelib/thread/qthread_p.h
@@ -379,8 +379,11 @@ class QScopedScopeLevelCounter
 {
     QThreadData *threadData;
 public:
-    QScopedScopeLevelCounter(QThreadData *threadData);
-    ~QScopedScopeLevelCounter();
+    inline QScopedScopeLevelCounter(QThreadData *threadData)
+        : threadData(threadData)
+    { ++threadData->scopeLevel; }
+    inline ~QScopedScopeLevelCounter()
+    { --threadData->scopeLevel; }
 };
 
 // thread wrapper for the main() thread
diff --git a/src/corelib/thread/qthread_unix.cpp b/src/corelib/thread/qthread_unix.cpp
index fc9ab3aa1a6..15851a6046b 100644
--- a/src/corelib/thread/qthread_unix.cpp
+++ b/src/corelib/thread/qthread_unix.cpp
@@ -8,6 +8,7 @@
 #include <private/qcoreapplication_p.h>
 #include <private/qcore_unix_p.h>
 #include "qdebug.h"
+#include "qloggingcategory.h"
 #include "qthreadstorage.h"
 #include <private/qtools_p.h>
 
@@ -404,7 +405,6 @@ void QThreadPrivate::finish()
         d->threadState = QThreadPrivate::Finishing;
         locker.unlock();
         emit thr->finished(QThread::QPrivateSignal());
-        qCDebug(lcDeleteLater) << "Sending deferred delete events as part of finishing thread" << thr;
         QCoreApplication::sendPostedEvents(nullptr, QEvent::DeferredDelete);
 
         void *data = &d->data->tls;
diff --git a/src/corelib/thread/qthread_win.cpp b/src/corelib/thread/qthread_win.cpp
index 8b902ec2cd6..137a609107a 100644
--- a/src/corelib/thread/qthread_win.cpp
+++ b/src/corelib/thread/qthread_win.cpp
@@ -230,7 +230,6 @@ void QThreadPrivate::finish(bool lockAnyway) noexcept
     if (lockAnyway)
         locker.unlock();
     emit thr->finished(QThread::QPrivateSignal());
-    qCDebug(lcDeleteLater) << "Sending deferred delete events as part of finishing thread" << thr;
     QCoreApplicationPrivate::sendPostedEvents(nullptr, QEvent::DeferredDelete, d->data);
     QThreadStorageData::finish(tls_data);
     if (lockAnyway)