add xcb plugin presence test

Author: darkmattercoder

Diff for: .gitignore

@@ -19,3 +19,5 @@ Makefile
 run-tests.sh
 tests.pro
 /.qmake.stash
+tests/build-*
+*.pro.user*

Diff for: tests/xcb-plugin/main.cpp

@@ -0,0 +1,15 @@
+#include <QDebug>
+#include <QDir>
+//#define PLUGIN_DIR "plugindir"
+int main() {
+  QString platformDir = QString(PLUGIN_DIR) + "\\platforms";
+  QDir pluginDir(platformDir);
+  QStringList platformPlugins = pluginDir.entryList();
+  qDebug() << "plugins found in file system: " << platformPlugins;
+  if (platformPlugins.contains("libqxcb.so")) {
+	qDebug() << "xcb plugin found";
+	return 0;
+  }
+  qDebug() << "xcb plugin not found";
+  return 1;
+}

Diff for: tests/xcb-plugin/xcb-plugin.pro

@@ -0,0 +1,7 @@
+QT += core
+QT -= gui
+TARGET = xcb-plugin
+CONFIG   += console
+TEMPLATE = app
+SOURCES += main.cpp
+DEFINES += PLUGIN_DIR=\\\"$$[QT_INSTALL_PLUGINS]\\\"