Do not register the same Qt version under several names

Do not get fooled by the same qmake being available (via
symlinks) in several places on the file system. Just register
each Qt version once.

Change-Id: I8d5efb80599a697c32a3ca3ab37924bc9ab523eb
Reviewed-by: Daniel Teske <daniel.teske@digia.com>

src/plugins/qtsupport/qtoptionspage.cpp

@@ -635,19 +635,24 @@ static QString filterForQmakeFileDialog()
 void QtOptionsPageWidget::addQtDir()
 {
     Utils::FileName qtVersion = Utils::FileName::fromString(
-                QFileDialog::getOpenFileName(this,
-                                             tr("Select a qmake executable"),
-                                             QString(),
-                                             filterForQmakeFileDialog(),
-                                             0,
-                                             QFileDialog::DontResolveSymlinks));
+                QFileInfo(QFileDialog::getOpenFileName(this,
+                                                       tr("Select a qmake executable"),
+                                                       QString(),
+                                                       filterForQmakeFileDialog(),
+                                                       0,
+                                                       QFileDialog::DontResolveSymlinks)).canonicalFilePath());
     if (qtVersion.isNull())
         return;
-    if (QtVersionManager::instance()->qtVersionForQMakeBinary(qtVersion)) {
+    BaseQtVersion *version = QtVersionManager::instance()->qtVersionForQMakeBinary(qtVersion);
+    if (version) {
         // Already exist
+        QMessageBox::warning(this, tr("Qt known"),
+                             tr("This Qt version was already registered as \"%1\".")
+                             .arg(version->displayName()));
+        return;
     }
 
-    BaseQtVersion *version = QtVersionFactory::createQtVersionFromQMakePath(qtVersion);
+    version = QtVersionFactory::createQtVersionFromQMakePath(qtVersion);
     if (version) {
         m_versions.append(version);
 

src/plugins/qtsupport/qtversionmanager.cpp

@@ -623,9 +623,8 @@ Utils::FileName QtVersionManager::findQMakeBinaryFromMakefile(const QString &mak
 #endif
                 // Is qmake still installed?
                 QFileInfo fi(qmakePath);
-                if (fi.exists()) {
-                    return Utils::FileName(fi);
-                }
+                if (fi.exists())
+                    return Utils::FileName::fromString(fi.canonicalFilePath());
             }
         }
     }