It's not needed, but makes the point for having a mutable lambda in the
first place.
Change-Id: I483862d6aee90bb62d4b5363c56a80bb05e14df7
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
This places the first through third parameters on the exact positions
that they will be used to perform the operations in the switch, saving
the compiler from generating a few instructions to move data around. All
ABIs Qt supports that pass any function parameters in registers at all
pass at least 4.
We keep the return type as void (instead of returning bool, for the
Compare case) so the compiler can apply tail-call optimizations for
those two typical cases.
PMF case: https://gcc.godbolt.org/z/9oP5boKfj
Function case: https://gcc.godbolt.org/z/e9vEzd5dj
Functor case: https://gcc.godbolt.org/z/s8Ejjra7P
Change-Id: I3e3bfef633af4130a03afffd175d3e3009c56323
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
After the recent changes we only have a single implementation of
QSlotObjectBase, which can handle free functions, member functions,
functors, and lambdas. Rename it to callable, and explicitly hide
the static implementation function so that it doesn't become a symbol
of static libraries using Qt.
Also rename makeSlotObject to makeCallableObject, and polish coding
style and comments in the qobjectdefs_impl header a bit.
Change-Id: Id19107cedfe9c624f807cd8089beb80e9eb99f50
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Add helper that allows us to determine the argument list and return type
of a functor. This triggers a compile time error if the functor has
operator()() overloads (we only support zero-argument call operators, but
there might be const/noexcept variations). Use that helper to declare a
ZeroArgFunctor type which also declares a ReturnType and Arguments alias.
Add a Callable alias that now combines FunctionPointer and ZeroArgFunctor
into a single type that we can then use to merge the specializations of
QMetaObject::invokeMethod.
[ChangeLog][Potentially source-incompatible changes] Using a functor
with several operator() overloads in QMetaObject::invokeMethod now causes
a compile time error. Qt would previously ignore const and noexcept
overloads and always call the mutable version on a copy of the functor.
Change-Id: I3eb62c1128014b729575540deab615469290daeb
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
Amends 642f799fc6 to avoid unnecessary
copies in between the calls to the QFunctorSlotObject construcotr. We
can't use a univeral reference in the QFunctorSlotObject constructor
as the call is not deduced. So provide two overloads for lvalue and
rvalue references instead.
The compile check in the test now no longer fails as we delay the
storage until one level later, but that's acceptable.
Change-Id: Ide95b4a73c70f6f47698dd1e95138aa5d48ee95d
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
Remove duplicate test and outdated comment about move-only functors,
and include return value in move-only functor test.
Change-Id: I58dffe0ccf3ec12e7e05e2c9588303da4a7e75ff
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Amend 3c6e9dcc623c9d7281a81174bb3a696e030f30a7 by making sure that
we explicitly move move-only functors into the slot object in the
respective tests, and that failing to do so doesn't compile.
Also add test coverage for mutable lambdas, which work as they do
with connected functors: the connection stores a copy, and calls
don't modify the original functor.
Change-Id: I637e6f407133e2f8f72109b3fe5369a11d19da93
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
This reverts commit 9958edba41, which
incorrectly tested a move-only functor without actually moving the
functor.
Change-Id: I3707f9f8e5055102f7edfb3e1cb9750978356dd7
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Amends 207aae5560 to make it easy to
create human-friendly error messages. Since the functor-accepting member
functions are not removed from the API, the first compile error will be
that there is no suitable overload of the makeSlotObject helper, which.
With the assert helper, the first error message is easier to understand.
Change-Id: I4878ec35a44ddfa5dc9d9e358d81c3fd40389c0c
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Move-only functors must never be passed by value, so fix the
QFunctorSlotObject constructor accordingly.
This then requires adjustments to the various QMetaMethod::invokeMethod
overloads, as those must also perfectly forwad the functor type.
Enable the previously failing test case for move-only functors.
Change-Id: I9c544fd3ddbc5e1da3ca193236291a9f83d86211
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Amend 207aae5560, as code checker
complained that we std::move'd a potential lvalue. This warning was
valid if the public API did not accept the functor parameter by value.
Fix this by consistently std::forward'ing the parameters through the
call stack, and add a compile-time test. Writing that test revealed that
the helper API didn't work with free functions, so fix that as well. It
also revealed that QFunctorSlotObject couldn't work with a const
functor, which is also fixed by this change.
We cannot support move-only functors with that change, as it requires
a change to QFunctorSlotObject that breaks the QMetaObject test.
Change-Id: Iafd747baf4cb0213ecedb391ed46b4595388182b
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
In most QObjectPrivate-subclasses, the Q_DECLARE_PUBLIC macro is used in
the private segment of the class declaration. In that case, the q_ptr
becomes a private member of the private class, and then the
QObjectPrivate::connect function can no longer be used, as it needs to
access the d_ptr.
Fix this by declaring QObjectPrivate, and the static-assert-helper, as
friends of the class using the Q_DECLARE_PUBLIC macro.
Adapt the QObject test by moving the Q_DECLARE_PUBLIC macro into
the private section of the test-private, and add a compile test.
Pick-to: 6.5 6.5.0
Change-Id: Ifc04be3b305221e138b1e08bb3a3838d871f4fcb
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Axel Spoerl <axel.spoerl@qt.io>
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
The code for the QMetaMethod queuedConnectionTypes overload relied on
QMetaMethod::parameterMetaType and QMetaType::flags() to detect whether
we're dealing with a pointer (and then use the VoidStar metatype instead).
However, if the type was incomplete when the slot was defined, and the
type was not registered when connect was called, we would not find a
metatype for the argument.
However, in that case we might still be able to handle the method, by
checking whether the type name of the arguments ends with a "*".
This patch does that, fixing a regression from 5.15.
Pick-to: 6.5 6.4 6.2
Fixes: QTBUG-108537
Change-Id: I54cc48a3343444480ab9094fe1ebaaa5aa75cee0
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
The patch includes the following replacements:
* QMetaType::type("name") -> QMetaType::fromType<Type>().id()
* QMetaProperty::type() -> QMetaProperty::typeId()
* QVariant::Type -> QMetaType::Type
* qRegisterMetaType<T>("name") -> qResigeterMetaType<T>()
* The static QMetaType::{load,save} methods are replaced with
non-static versions
* Replace QCOMPARE(property.type(), QVariant::UserType) with
QCOMPARE_GT(property.typeId(), QMetaType::User), because the
deprecated type() method was treating each custom type
(id >= QVariant::UserType) as QVariant::UserType, while the
typeId() method simply returns the actual id.
As a drive-by: remove unneeded QMetaType registration tests
as we have tst_QMetaType to check it.
Task-number: QTBUG-104858
Change-Id: Ia08e002efdf07ff83366a5193164dba96a956f9a
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
The QObjectPrivate::declarativeData member is stored in a union with
currentChildBeingDeleted. The QObject destructor always sets the
currentChildBeingDeleted member of the union. It also sets the
isDeletingChildren bool, which is the only way to find out which union
member we can safely access.
While the QObject destructor is deleting children and isDeletingChildren
is set, we must not access the declarativeData member of the union.
Add a test case that initializes the function pointers for the
declarative handlers and constructs a situation where an object
emits a signal while it is destroying children.
Fixes: QTBUG-105286
Pick-to: 6.4 6.3 6.3.2 6.2 5.15
Change-Id: Iea5ba2f7843b6926a8d157be166e6044d98d6c02
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
The new name describes the behavior in a better way.
[ChangeLog][Build System] The QT_DISABLE_DEPRECATED_BEFORE macro is
renamed to QT_DISABLE_DEPRECATED_UP_TO. The old name is deprecated, but
is still recognized if it is defined during configuration and the new
name is not defined.
Task-number: QTBUG-104944
Change-Id: Ifc34323e0bbd9e3dc2f86c3e80d4d0940ebccbb8
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
CMakeLists.txt and .cmake files of significant size
(more than 2 lines according to our check in tst_license.pl)
now have the copyright and license header.
Existing copyright statements remain intact
Task-number: QTBUG-88621
Change-Id: I3b98cdc55ead806ec81ce09af9271f9b95af97fa
Reviewed-by: Jörg Bornemann <joerg.bornemann@qt.io>
QMetaType can register a converter from a smart pointer class to
QObject *. The code tries to do so even if the smart pointer is
actually holding a pointer to a _const_ QObject
(e.g. shared_ptr<const QObject>), causing a compile error:
../src/qt5/qtbase/build/include/QtCore/../../../src/corelib/kernel/qmetatype.h:1208:32: error: invalid conversion from ‘const QObject*’ to ‘QObject*’ [-fpermissive]
1208 | return p.operator->();
| ~~~~~~~~~~~~^~
| |
| const QObject*
Disable the conversion if indeed the source is const qualified.
Change-Id: I9e9bc5992f74131e5cfd6ece9b83d4f26d370e92
Fixes: QTBUG-103741
Pick-to: 6.2 6.3
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Replace the current license disclaimer in files by
a SPDX-License-Identifier.
Files that have to be modified by hand are modified.
License files are organized under LICENSES directory.
Task-number: QTBUG-67283
Change-Id: Id880c92784c40f3bbde861c0d93f58151c18b9f1
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
Reviewed-by: Jörg Bornemann <joerg.bornemann@qt.io>
We don't support it any more. I don't think it has ever properly
compiled Qt 6 (and it's no longer working for me against GCC 12's
libstdc++ headers). If you report a bug against it, Intel support's
first question is if you can try instead the new Clang/LLVM-based oneAPI
C++ compiler.
So we support only that one, which identifies itself as Q_CC_CLANG.
Change-Id: I5ff8e16fcdcb4ffd9ab6fffd16eb57a092c8439e
Reviewed-by: Marc Mutz <marc.mutz@qt.io>
Connecting to a non-signal should fail, but apparently it doesn't on
Windows+MSVC under certain conditions.
Task-number: QTBUG-101761
Change-Id: I3e014660e4e5b287242e32307f677bb22ab10a39
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
In no particular order:
- use the variable field width feature of QString::asprintf() to
generate the indentation implicitly, instead of fill()ing a
QByteArray with the desired number of spaces
- just default-construct 'flags', don't assign an empty string
- use qUtf16Printable() to avoid funneling UTF-16 data through 8-bit
encodings
- use a C++11 ranged for instead of a counted loop
- remove a pointless isEmpty() guard (the loop won't execute when the
children().isEmpty())
- avoid copying object->children() (returns by cref, so it's also ok
to stuff it directly into the ranged for loop).
Add a test.
Pick-to: 6.3
Change-Id: Ie7314713cb48de7e890cdee0760c0361dd24fd18
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Not MSVC, but pretends to be.
Pick-to: 6.3 6.2
Change-Id: I5c201dd917e79a22d6ef15715bf1d3a7010d123e
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
The old-syle signal-slot syntax had the advantage of not delivering
signals to slots in derived classes after that derived class's
destructor had finished running (because we called via the virtual
qt_metacall). The new syntax made no checks, so a conversion from the
old to the new syntax may introduce crashes or other data corruptions at
runtime if the destructor had completed.
This commit introduces a Q_ASSERT to print the class name that the
object is not any more. Since this is in inline code, this should get
enabled for users' debug modes and does not therefore depend on Qt being
built in debug mode.
It required some Private classes to be adapted to the new form, by
exposing the public q_func() in the public: part.
Pick-to: 6.2
Fixes: QTBUG-33908
Change-Id: Iccb47e5527544b6fbd75fffd16b874cdc08c1f3e
Reviewed-by: Marc Mutz <marc.mutz@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>
Don't rely on transitive include from qobject.h, which will go away.
Change-Id: I99dd97ff4fb1d0632d040daab0bffa2d7b85d3ae
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
This define used to be set for the entirety of the Qt build but
was lost during the qmake->CMake transition. Re-enable it.
Change-Id: Idc4cb6ada485158559485b60f62f76439550b255
Pick-to: 6.2
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
- process environment/DNS are OFF for INTEGRITY
Task-number: QTBUG-96176
Pick-to: 6.2
Change-Id: I189a97f88c96a428586c31a66b8d250e04482900
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
Instead of making it return a non-useful nullptr.
Change-Id: Ie72b0dd0fbe84d2caae0fffd16a245cce5ea65f1
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
The connect() documentation makes it clear that UniqueConnection does
not work with free functions / function objects and the like; only with
actual PMFs. Rather than silently *ignoring* the flag, be vocal about its
presence by warning, and make the connection fail (as the user has
passed an illegal argument).
[ChangeLog][QtCore][QObject] QObject::connect() now will refuse to
connect a signal to a free function / function object if UniqueConnection
is passed. Note that UniqueConnection has never worked for such
connections -- the flag was simply ignored, and they were established
multiple times. Now, the flag is not ignored and results in a connection
failure (as well as a runtime warning by Qt).
Change-Id: I6509667018c74f9bd24910cde0a1b16c5f84f064
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
There are few slots whose lambdas are empty; most will at least
capture [this]. But there are a few in Qt examples that do, e.g. []{
qApp->quit(); }. Logging is also an example. So go the extra mile and
optimize for empty functors by inheriting from them as opposed to
storing them in a member variable.
Change-Id: I3904f10db5ebe904ba889d29c08569edd804df3b
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Outside tests, all in-tree callers of QObject::findChildren() pass no
name to match, and in my experience that is also true for the vast
majority of out-of-tree users.
Avoid the temporary QString creation in the caller and the repeated
QString::isNull() checks in the implementation by overloading
findChildren() without a name argument and checking for name.isNull()
only once, forking off into separate helper functions.
Adjust in-tree callers that used an explicit `QString()` argument in
order to pass options, which goes to show that `name` should never
have been the first argument of findChilden() in the first place, even
though I appreciate the symmetry with findChild() (the use-cases of
which, however, are radically different).
Change a `findChildren().size() == 0` call found while scanning for
findChildren() calls to `!findChild()` as a drive-by.
Modernize loops in the various qt_qFindChild{,ren}_helper() overloads
to match how the new code looks.
[ChangeLog][QtCore][QObject] Added findChildren() overload taking no
name (thus optimizing this common case).
Change-Id: Ifc56e5438023d079b40c67f11ae274a3e128ad5e
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
Extended QObjectPrivate::ExtraData to store a pointer
to its parent, and reimplemented qGetBindingStorage()
function for QObjectPrivate::ExtraData.
This allows to use Q_OBJECT_COMPAT_PROPERTY macro
for a property, stored in QObjectPrivate::ExtraData
and solves all the problems with calling a custom
setter.
Task-number: QTBUG-85520
Change-Id: I40e01c29430846359ef9160fa1ae97c702be9a18
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
Reviewed-by: Sona Kurazyan <sona.kurazyan@qt.io>
Compilers are catching up, so some #if 0 codepaths can now be
conditionally enabled.
Change-Id: Ia9e87a096bc2ae4789ab390a9170d9c1eb9690d6
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>
Q_CC_GNU is defined on compilers that masquerade as GCC (Clang, ICC),
so using it to work around GCC-specific bugs is wrong. Introduce a
local define for _only_ GCC and use it in place of Q_CC_GNU.
Drive by: version-fence a test we now know it's been fixed upstream,
and correct the link to the corresponding bug report.
Pick-to: 5.15 6.0 6.1
Change-Id: I9059d6e6bf86157aca71590ac22afb1a1c114313
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
The code in qtdeclarative did not do anything at all anymore.
Change-Id: Idd97145cb74aeb4f43dfce2f282a765e90945073
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Original QML-specific connection mechanism ignores the receiver argument
and uses sender as receiver. This causes uncontrollable memory growth
in certain cases as connections on receiver persist even after receiver
is destroyed
New connect() with receiver parameter uses underlying API correctly,
disconnect is provided for the symmetry (not sure it's really needed)
Task-number: QTBUG-86368
Pick-to: 5.15 6.0
Change-Id: I4580d75b617cb2c4dfb971a4dfb8e943e325572b
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Those serve no purpose anymore, now that the .pro files are gone.
Task-number: QTBUG-88742
Change-Id: I39943327b8c9871785b58e9973e4e7602371793e
Reviewed-by: Cristian Adam <cristian.adam@qt.io>
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
Reviewed-by: Kai Koehne <kai.koehne@qt.io>
Remove the qmake project files for most of Qt.
Leave the qmake project files for examples, because we still test those
in the CI to ensure qmake does not regress.
Also leave the qmake project files for utils and other minor parts that
lack CMake project files.
Task-number: QTBUG-88742
Change-Id: I6cdf059e6204816f617f9624f3ea9822703f73cc
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Kai Koehne <kai.koehne@qt.io>
Complete search and replace of QtTest and QtTest/QtTest with QTest, as
QtTest includes the whole module. Replace all such instances with
correct header includes. See Jira task for more discussion.
Fixes: QTBUG-88831
Change-Id: I981cfae18a1cabcabcabee376016b086d9d01f44
Pick-to: 6.0
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
Except for types marked as unresolved, we're doing it anyway - the only
difference is that now we skip looking up the metatype by typeid.
[ChangeLog][QMetaProperty][Important Behavior Change]
QMetaProperty::typeName returns now always the same name as name() of the
corresponding metatype. This can cause a change for enum properties
which were not fully-qualified.
Change-Id: I1f57743948b7262ac06095d3bbc838d620f6e481
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
This reverts commit 1918c689d7.
The template gets always instantiated in QObjectPrivate::connect, even
if the connection types is not Qt::(Blocking)QueuedConnection. For
non-queued connections we however support using incomplete types in
connect. The only way to fix this would be to make the connection type a
template parameter of QObjectPrivate::connect (or at lesat pass some
compile time constant indicating "blocking"-ness) along, so that we can
use if constexpr instead of if. As all involved classes are private, we
can postpone investigating this solution to 6.1
Change-Id: Ieffaf015f8e60ca6ac6f85eb9e2756e480060b4f
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
This time based on grepping to also include documentation, tests and
examples previously missed by the automatic tool.
Change-Id: Ied1703f4bcc470fbc275f759ed5b7c588a5c4e9f
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>
Modify special case locations to use the new API as well.
Clean up some stale .prev files that are not needed anymore.
Clean up some project files that are not used anymore.
Task-number: QTBUG-86815
Change-Id: I9947da921f98686023c6bb053dfcc101851276b5
Reviewed-by: Joerg Bornemann <joerg.bornemann@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
They were disabled in ad0e3e26fa,
but that was probably accidental.
Change-Id: Ia9cbccfbeecfe84768c3465f5699ed44b7f932a5
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>
Remove around 1000 compiler warnings about missing overrides
in our auto tests.
This significantly reduce the compiler warning noise in our auto
tests, so that one can actually better see the real problems
inbetween.
Change-Id: Id0c04dba43fcaf55d8cd2b5c6697358857c31bf9
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
If one needed to listen to a signal just once, one had to
store the QMetaObject::Connection object returned by connect()
and use it to disconnect the slot after the first signal
activation.
This has led to a proliferation of using wrappers (and enough
TMP); they usually look like this:
1) create a shared_ptr<QMO::Connection>, allocating its payload;
2) create a lambda, capturing the shared_ptr by value;
3) in the lambda, disconnect the connection (through the shared_ptr),
and call the actual slot;
4) connect the signal to the lambda, storing the returned
QMO::Connection into the shared_ptr.
This is expensive, error prone for newcomers, and tricky to
support as a general facility inside one's projects.
We can do better, just support single shot connections right
in QObject.
[ChangeLog][QtCore][QObject] Added the Qt::SingleShotConnection
flag. When a connection is established with this flag set,
the slot is going to be activated at most once; when the signal
is emitted, the connection gets automatically broken by Qt.
Change-Id: I5f5feeae7f76c9c3d6323d841efba81c8f98ce7e
Fixes: QTBUG-44219
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
