4 files changed, 34 insertions, 19 deletions
diff --git a/src/corelib/kernel/qmetacontainer.cpp b/src/corelib/kernel/qmetacontainer.cpp
index 4b4ea06d8b9..6173198a972 100644
--- a/src/corelib/kernel/qmetacontainer.cpp
+++ b/src/corelib/kernel/qmetacontainer.cpp
@@ -210,7 +210,7 @@ void QMetaContainer::destroyIterator(const void *iterator) const
  */
 bool QMetaContainer::compareIterator(const void *i, const void *j) const
 {
-    return hasIterator() ? d_ptr->compareIteratorFn(i, j) : false;
+    return i == j || (hasIterator() && d_ptr->compareIteratorFn(i, j));
 }
 
 /*!
@@ -249,7 +249,7 @@ void QMetaContainer::advanceIterator(void *iterator, qsizetype step) const
  */
 qsizetype QMetaContainer::diffIterator(const void *i, const void *j) const
 {
-    return hasIterator() ? d_ptr->diffIteratorFn(i, j) : 0;
+    return (i != j && hasIterator()) ?  d_ptr->diffIteratorFn(i, j) : 0;
 }
 
 /*!
@@ -327,7 +327,7 @@ void QMetaContainer::destroyConstIterator(const void *iterator) const
  */
 bool QMetaContainer::compareConstIterator(const void *i, const void *j) const
 {
-    return hasConstIterator() ? d_ptr->compareConstIteratorFn(i, j) : false;
+    return i == j || (hasConstIterator() && d_ptr->compareConstIteratorFn(i, j));
 }
 
 /*!
@@ -366,7 +366,7 @@ void QMetaContainer::advanceConstIterator(void *iterator, qsizetype step) const
  */
 qsizetype QMetaContainer::diffConstIterator(const void *i, const void *j) const
 {
-    return hasConstIterator() ?  d_ptr->diffConstIteratorFn(i, j) : 0;
+    return (i != j && hasConstIterator()) ?  d_ptr->diffConstIteratorFn(i, j) : 0;
 }
 
 QT_END_NAMESPACE
diff --git a/src/corelib/kernel/qobject.cpp b/src/corelib/kernel/qobject.cpp
index 02c9f00f301..607dc23f56c 100644
--- a/src/corelib/kernel/qobject.cpp
+++ b/src/corelib/kernel/qobject.cpp
@@ -2696,23 +2696,38 @@ static void err_method_notfound(const QObject *object,
         case QSIGNAL_CODE: type = "signal"; break;
     }
     const char *loc = extract_location(method);
+    const char *err;
     if (strchr(method, ')') == nullptr) // common typing mistake
-        qCWarning(lcConnect, "QObject::%s: Parentheses expected, %s %s::%s%s%s", func, type,
-                  object->metaObject()->className(), method + 1, loc ? " in " : "", loc ? loc : "");
+        err = "Parentheses expected,";
     else
-        qCWarning(lcConnect, "QObject::%s: No such %s %s::%s%s%s", func, type,
-                  object->metaObject()->className(), method + 1, loc ? " in " : "", loc ? loc : "");
+        err = "No such";
+    qCWarning(lcConnect, "QObject::%s: %s %s %s::%s%s%s", func, err, type,
+              object->metaObject()->className(), method + 1, loc ? " in " : "", loc ? loc : "");
+}
+
+enum class ConnectionEnd : bool { Sender, Receiver };
+Q_DECL_COLD_FUNCTION
+static void err_info_about_object(const char *func, const QObject *o, ConnectionEnd end)
+{
+    if (!o)
+        return;
+    const QString name = o->objectName();
+    if (name.isEmpty())
+        return;
+    const bool sender = end == ConnectionEnd::Sender;
+    qCWarning(lcConnect, "QObject::%s:  (%s name:%*s'%ls')",
+              func,
+              sender ? "sender" : "receiver",
+              sender ? 3 : 1, // ← length of generated whitespace
+              "",
+              qUtf16Printable(name));
 }
 
 Q_DECL_COLD_FUNCTION
 static void err_info_about_objects(const char *func, const QObject *sender, const QObject *receiver)
 {
-    QString a = sender ? sender->objectName() : QString();
-    QString b = receiver ? receiver->objectName() : QString();
-    if (!a.isEmpty())
-        qCWarning(lcConnect, "QObject::%s:  (sender name:   '%s')", func, a.toLocal8Bit().data());
-    if (!b.isEmpty())
-        qCWarning(lcConnect, "QObject::%s:  (receiver name: '%s')", func, b.toLocal8Bit().data());
+    err_info_about_object(func, sender, ConnectionEnd::Sender);
+    err_info_about_object(func, receiver, ConnectionEnd::Receiver);
 }
 
 Q_DECL_COLD_FUNCTION
diff --git a/src/corelib/kernel/qobject_impl.h b/src/corelib/kernel/qobject_impl.h
index b57d7e50ccd..34e6bd84f3f 100644
--- a/src/corelib/kernel/qobject_impl.h
+++ b/src/corelib/kernel/qobject_impl.h
@@ -1,8 +1,6 @@
 // Copyright (C) 2016 The Qt Company Ltd.
 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
-#ifndef Q_QDOC
-
 #ifndef QOBJECT_H
 #error Do not include qobject_impl.h directly
 #endif
@@ -41,5 +39,3 @@ namespace QtPrivate {
 
 
 QT_END_NAMESPACE
-
-#endif
diff --git a/src/corelib/kernel/qpermissions.cpp b/src/corelib/kernel/qpermissions.cpp
index bbcea8338ca..6767917e176 100644
--- a/src/corelib/kernel/qpermissions.cpp
+++ b/src/corelib/kernel/qpermissions.cpp
@@ -124,7 +124,11 @@ Q_LOGGING_CATEGORY(lcPermissions, "qt.permissions", QtWarningMsg);
     The relevant permission names are described in the documentation
     for each permission type.
 
-    \sa {Qt Creator: Editing Manifest Files}
+    \note When using this API, the \c{<!-- %%INSERT_PERMISSIONS -->} tag must be present in
+    the AndroidManifest.xml. For further information on the use of this tag,
+    see \l {Qt Permissions and Features}
+
+    \sa {Qt Creator: Editing Manifest Files}.
 
     \section1 Available Permissions