cmake-gui: Teach Qt5 where plugins are when launched through a symlink

When we are on OSX and we are launching cmake-gui from a symlink, the
application will fail to launch as it can't find the qt.conf file which
tells it what the name of the plugin folder is. We need to add this path
BEFORE the application is constructed as that is what triggers the
searching for the platform plugins

1 files changed, 34 insertions, 0 deletions

diff --git a/Source/QtDialog/CMakeSetup.cxx b/Source/QtDialog/CMakeSetup.cxx
index c3c14689a5..c849d5292a 100644
--- a/Source/QtDialog/CMakeSetup.cxx
+++ b/Source/QtDialog/CMakeSetup.cxx
@@ -19,6 +19,7 @@
 #include <QApplication>
 #include <QDir>
 #include <QLocale>
+#include <QString>
 #include <QTextCodec>
 #include <QTranslator>
 #include <cmsys/CommandLineArguments.hxx>
@@ -40,6 +41,7 @@ static const char* cmDocumentationOptions[][2] = { { 0, 0 } };
 
 #if defined(Q_OS_MAC)
 static int cmOSXInstall(std::string dir);
+static void cmAddPluginPath();
 #endif
 
 int main(int argc, char** argv)
@@ -81,6 +83,15 @@ int main(int argc, char** argv)
   }
 #endif
 
+// When we are on OSX and we are launching cmake-gui from a symlink, the
+// application will fail to launch as it can't find the qt.conf file which
+// tells it what the name of the plugin folder is. We need to add this path
+// BEFORE the application is constructed as that is what triggers the
+// searching for the platform plugins
+#if defined(Q_OS_MAC)
+  cmAddPluginPath();
+#endif
+
   QApplication app(argc, argv);
 
   setlocale(LC_NUMERIC, "C");
@@ -215,4 +226,27 @@ static int cmOSXInstall(std::string dir)
     ? 0
     : 1;
 }
+
+// Locate the PlugIns directory and add it to the QApplication library paths.
+// We need to resolve all symlinks so we have a known relative path between
+// MacOS/CMake and the PlugIns directory.
+//
+// Note we are using cmSystemTools since Qt can't provide the path to the
+// executable before the QApplication is created, and that is when plugin
+// searching occurs.
+static void cmAddPluginPath()
+{
+  std::string const& path = cmSystemTools::GetCMakeGUICommand();
+  if (path.empty()) {
+    return;
+  }
+  std::string const& realPath = cmSystemTools::GetRealPath(path);
+  QFileInfo appPath(QString::fromLocal8Bit(realPath.c_str()));
+  QDir pluginDir = appPath.dir();
+  bool const foundPluginDir = pluginDir.cd("../PlugIns");
+  if (foundPluginDir) {
+    QApplication::addLibraryPath(pluginDir.path());
+  }
+}
+
 #endif