Escape HTML tags in window caption in Aurorae and Killer

The unescaped tags are interpreted as HTML by Aurorae decorations
and the KWin killer. Escaping the tags ensures that the text is not
rendered incorrectly.

BUG: 293657
FIXED-IN: 4.9.0
REVIEW: 104989

clients/aurorae/src/qml/aurorae.qml

@@ -151,6 +151,7 @@ Decoration {
     Text {
         id: caption
         text: decoration.caption
+        textFormat: Text.PlainText
         horizontalAlignment: auroraeTheme.horizontalAlignment
         verticalAlignment: auroraeTheme.verticalAlignment
         elide: Text.ElideRight

killer/killer.cpp

@@ -32,6 +32,8 @@ DEALINGS IN THE SOFTWARE.
 #include <X11/Xlib.h>
 #include <QX11Info>
 #include <QProcess>
+// TODO: remove with Qt 5, only for HTML escaping the caption
+#include <QTextDocument>
 #include <signal.h>
 #include <errno.h>
 
@@ -66,6 +68,9 @@ int main(int argc, char* argv[])
         KCmdLineArgs::usageError(i18n("This helper utility is not supposed to be called directly."));
         return 1;
     }
+    if (Qt::mightBeRichText(caption)) {
+        caption = Qt::escape(caption);
+    }
     QString question = i18n(
                            "<p>The window \"<b>%2</b>\" is not responding. "
                            "It belongs to the application <b>%1</b> (Process ID = %3, hostname = %4).</p>"