Remove Qt6::Core5Compat

[MartinDelille]

Is there any plan to remove Qt6::Core5Compat dependency ?

[dibok]

Are you referring to:
../Qt/6.5.1/gcc_64/lib/libQt6Core5Compat.so.6: error adding symbols: DSO missing from command line
Today was my first attempt to use quazip. I was struggled to compile .so library (it could not find FindQt6.cmake) for Qt6 but finally done that with:
cmake -D QUAZIP_QT_MAJOR_VERSION=6 -DCMAKE_PREFIX_PATH="/home/user/Qt6/6.5.1/gcc_64/lib/cmake"
I have now all .so libs in my project tree:

libquazip1-qt6.so
libquazip1-qt6.so.1.4
libquazip1-qt6.so.1.4.0

My .pro file:

QT       += core gui

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

CONFIG += c++17

# You can make your code fail to compile if it uses deprecated APIs.
# In order to do so, uncomment the following line.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0

SOURCES += \
    main.cpp \
    mainwindow.cpp \
    quazip/quazip/JlCompress.cpp \
    quazip/quazip/qioapi.cpp \
    quazip/quazip/quaadler32.cpp \
    quazip/quazip/quachecksum32.cpp \
    quazip/quazip/quacrc32.cpp \
    quazip/quazip/quagzipfile.cpp \
    quazip/quazip/quaziodevice.cpp \
    quazip/quazip/quazip.cpp \
    quazip/quazip/quazipdir.cpp \
    quazip/quazip/quazipfile.cpp \
    quazip/quazip/quazipfileinfo.cpp \
    quazip/quazip/quazipnewinfo.cpp

HEADERS += \
    mainwindow.h \
    quazip/quazip/JlCompress.h \
    quazip/quazip/ioapi.h \
    quazip/quazip/minizip_crypt.h \
    quazip/quazip/quaadler32.h \
    quazip/quazip/quachecksum32.h \
    quazip/quazip/quacrc32.h \
    quazip/quazip/quagzipfile.h \
    quazip/quazip/quaziodevice.h \
    quazip/quazip/quazip.h \
    quazip/quazip/quazip_global.h \
    quazip/quazip/quazip_qt_compat.h \
    quazip/quazip/quazipdir.h \
    quazip/quazip/quazipfile.h \
    quazip/quazip/quazipfileinfo.h \
    quazip/quazip/quazipnewinfo.h \
    quazip/quazip/unzip.h \
    quazip/quazip/zip.h

FORMS += \
    mainwindow.ui

# Default rules for deployment.
qnx: target.path = /tmp/$${TARGET}/bin
else: unix:!android: target.path = /opt/$${TARGET}/bin
!isEmpty(target.path): INSTALLS += target

LIBS += -lz

win32:CONFIG(release, debug|release): LIBS += -L$$PWD/quazip/quazip/release/ -lquazip1-qt6
else:win32:CONFIG(debug, debug|release): LIBS += -L$$PWD/quazip/quazip/debug/ -lquazip1-qt6
else:unix: LIBS += -L$$PWD/quazip/quazip/ -lquazip1-qt6

INCLUDEPATH += $$PWD/quazip/quazip
DEPENDPATH += $$PWD/quazip/quazip

But I stuck on two errors:

:-1: error: quazip.o: undefined reference to symbol '_ZNK10QTextCodec11fromUnicodeERK7QString@@Qt_6'
:-1: error: /home/user/Qt6/6.5.1/gcc_64/lib/libQt6Core5Compat.so.6: error adding symbols: DSO missing from command line
:-1: error: collect2: error: ld returned 1 exit status

I'm on linux Mint and at this point google doesn't find any solution :(

[MartinDelille]

Yes QTextCodec::fromUnicode() is the reason Qt6::Core5Compat is required. I personally moved to minizip since Core5Compat was an issue on my project.

[cen1]

I looked into this for a bit.

QTextCodec is used all over the place, including public facing methods so it would warrant minor, if not major version bump because it might break existing code.

Second thing is how to go about refactoring this. Doing it in existing codebase by ifdefs and macros seems like a terrible idea. Maybe master should start tracking the current Qt version and drop support for older versions, while at the same time keeping a qt5 branch which would receive only critical updates. They could be tagged 6.X and 5.X respectively.

Thoughts?

[geustache]

Hello
I submit a pull request about that

[OgreTransporter]

I think it makes sense to remove the Qt 5 Core Compatibility APIs. Qt 5 reaches EOL on May 26, 2025, and that's the extra extended support you have to buy. After that, Qt 5 is history. Since QuaZip is also feature complete, it makes more sense to adapt the code to Qt 6 and possibly keep Qt 5 parts with macros. Qt 4 already reached EOL on December 19, 2015.