Use xcb-icccm to read the name property

Summary:
The KWindowSystem call which we used doesn't work on Wayland as it's only
implemented in the xcb variant and cannot be made available for Wayland
in an easy way as it is still XLib based.

This change turns the optional XCB-ICCCM dependency in a required one
and thus can use the functionality provided by said library to implement
what KWindowSystem provided.

BUG: 382789

Test Plan: New test case which failed with old code

Reviewers: #kwin, #plasma

Subscribers: plasma-devel, kwin

Tags: #kwin

Differential Revision: https://phabricator.kde.org/D7046

CMakeLists.txt

@@ -233,7 +233,6 @@ find_package(XCB 1.10
         SHM
         GLX
         CURSOR
-    OPTIONAL_COMPONENTS
         ICCCM
 )
 set_package_properties(XCB PROPERTIES TYPE REQUIRED)
@@ -570,6 +569,7 @@ set(kwin_XCB_LIBS
     XCB::KEYSYMS
     XCB::SHM
     XCB::GLX
+    XCB::ICCCM
 )
 
 set(kwin_WAYLAND_LIBS

autotests/integration/x11_client_test.cpp

@@ -52,6 +52,7 @@ private Q_SLOTS:
     void testFocusInWithWaylandLastActiveWindow();
     void testX11WindowId();
     void testCaptionChanges();
+    void testCaptionWmName();
 };
 
 void X11ClientTest::initTestCase()
@@ -427,5 +428,27 @@ void X11ClientTest::testCaptionChanges()
     c.reset();
 }
 
+void X11ClientTest::testCaptionWmName()
+{
+    // this test verifies that a caption set through WM_NAME is read correctly
+
+    // open glxgears as that one only uses WM_NAME
+    QSignalSpy clientAddedSpy(workspace(), &Workspace::clientAdded);
+    QVERIFY(clientAddedSpy.isValid());
+
+    QProcess glxgears;
+    glxgears.start(QStringLiteral("glxgears"));
+    QVERIFY(glxgears.waitForStarted());
+
+    QVERIFY(clientAddedSpy.wait());
+    QCOMPARE(clientAddedSpy.count(), 1);
+    QCOMPARE(workspace()->clientList().count(), 1);
+    Client *glxgearsClient = workspace()->clientList().first();
+    QCOMPARE(glxgearsClient->caption(), QStringLiteral("glxgears"));
+
+    glxgears.terminate();
+    QVERIFY(glxgears.waitForFinished());
+}
+
 WAYLANDTEST_MAIN(X11ClientTest)
 #include "x11_client_test.moc"

client.cpp

@@ -52,6 +52,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 // XLib
 #include <X11/Xutil.h>
 #include <fixx11h.h>
+#include <xcb/xcb_icccm.h>
 // system
 #include <unistd.h>
 #include <signal.h>
@@ -1411,12 +1412,30 @@ void Client::fetchName()
     setCaption(readName());
 }
 
+static inline QString readNameProperty(xcb_window_t w, xcb_atom_t atom)
+{
+    const auto cookie = xcb_icccm_get_text_property_unchecked(connection(), w, atom);
+    xcb_icccm_get_text_property_reply_t reply;
+    if (xcb_icccm_get_wm_name_reply(connection(), cookie, &reply, nullptr)) {
+        QString retVal;
+        if (reply.encoding == atoms->utf8_string) {
+            retVal = QString::fromUtf8(QByteArray(reply.name, reply.name_len));
+        } else if (reply.encoding == XCB_ATOM_STRING) {
+            retVal = QString::fromLocal8Bit(QByteArray(reply.name, reply.name_len));
+        }
+        xcb_icccm_get_text_property_reply_wipe(&reply);
+        return retVal.simplified();
+    }
+    return QString();
+}
+
 QString Client::readName() const
 {
     if (info->name() && info->name()[0] != '\0')
         return QString::fromUtf8(info->name()).simplified();
-    else
-        return KWindowSystem::readNameProperty(window(), XCB_ATOM_WM_NAME).simplified();
+    else {
+        return readNameProperty(window(), XCB_ATOM_WM_NAME);
+    }
 }
 
 // The list is taken from http://www.unicode.org/reports/tr9/ (#154840)
@@ -1487,7 +1506,7 @@ void Client::fetchIconicName()
     if (info->iconName() && info->iconName()[0] != '\0')
         s = QString::fromUtf8(info->iconName());
     else
-        s = KWindowSystem::readNameProperty(window(), XCB_ATOM_WM_ICON_NAME);
+        s = readNameProperty(window(), XCB_ATOM_WM_ICON_NAME);
     if (s != cap_iconic) {
         bool was_set = !cap_iconic.isEmpty();
         cap_iconic = s;