fix: read plasmashell version more reliably

In some cases, `plasmashell -v` crashes, which makes `readAllStandardOutput`
fail, although the version is printed out by the process before crashing.
See https://bugs.kde.org/show_bug.cgi?id=467696 and
https://bugreports.qt.io/browse/QTBUG-112258 for the details of the crash.

Instead, read the libtaskmanager version from CMake, which is much more
reliable.

.kde-ci.yml

@@ -26,3 +26,4 @@ Dependencies:
     'frameworks/kwayland': '@latest'
     'frameworks/kwindowsystem': '@latest'
     'frameworks/kxmlgui': '@latest'
+    'plasma/plasma-workspace': '@same'

CMakeLists.txt

@@ -36,6 +36,9 @@ find_package(KF5 ${KF5_MIN_VERSION} REQUIRED COMPONENTS
     Activities Archive CoreAddons GuiAddons Crash DBusAddons Declarative GlobalAccel Kirigami2
     I18n IconThemes KIO NewStuff Notifications Plasma PlasmaQuick Wayland WindowSystem XmlGui)
 
+find_package(LibTaskManager REQUIRED)
+add_definitions(-DPLASMA_WORKSPACE_VERSION="${LibTaskManager_VERSION}")
+   
 find_package(X11 REQUIRED)
 set_package_properties(X11 PROPERTIES DESCRIPTION "X11 libraries"
     URL "http://www.x.org"

declarativeimports/core/environment.cpp

@@ -61,25 +61,15 @@ uint Environment::makeVersion(uint major, uint minor, uint release) const
 uint Environment::identifyPlasmaDesktopVersion()
 {
     //! Identify Plasma Desktop version
-    QProcess process;
-    process.start("plasmashell", QStringList() << "-v");
-    process.waitForFinished();
-    QString output(process.readAllStandardOutput());
-
-    QStringList stringSplit = output.split(" ");
-
-    if (stringSplit.count() >= 2) {
-        qDebug() << " /////////////////////////";
-        QString cleanVersionString = stringSplit[1].remove("\n");
-        QStringList plasmaDesktopVersionParts = cleanVersionString.split(".");
+    QStringList plasmaDesktopVersionParts = QString(PLASMA_WORKSPACE_VERSION).split(".");
 
     if (plasmaDesktopVersionParts.count() == 3) {
+        qDebug() << " /////////////////////////";
         uint maj = plasmaDesktopVersionParts[0].toUInt();
         uint min = plasmaDesktopVersionParts[1].toUInt();
         uint rel = plasmaDesktopVersionParts[2].toUInt();
 
         if (maj > 0) {
-
             uint desktopVersion = makeVersion(maj, min, rel);
 
             QString message("Plasma Desktop version:  " + QString::number(maj) + "."
@@ -90,7 +80,6 @@ uint Environment::identifyPlasmaDesktopVersion()
 
             return desktopVersion;
         }
-        }
 
         qDebug() << " /////////////////////////";
     }