Fix importing adding a empty spec argument to qmake

src/plugins/qt4projectmanager/projectloadwizard.cpp

@@ -69,15 +69,20 @@ ProjectLoadWizard::ProjectLoadWizard(Qt4Project *project, QWidget *parent, Qt::W
 
         QString versionSpec = m_importVersion->sourcePath() + "/mkspecs/" + m_importVersion->mkspec();
         QString parsedSpec = Qt4Project::extractSpecFromArgumentList(m_additionalArguments);
-        QString parsedSpecOrginal = parsedSpec;
-        if (QFileInfo(parsedSpec).isRelative())
-            parsedSpec = QDir::cleanPath(directory + "/" + parsedSpec);
-        m_additionalArguments = Qt4Project::removeSpecFromArgumentList(m_additionalArguments);
-        if (parsedSpec != versionSpec) {
-            m_additionalArguments.prepend(parsedSpecOrginal);
-            m_additionalArguments.prepend("-spec");
-        }
 
+        // Compare mkspecs and add to additional arguments
+        if (parsedSpec.isEmpty()) {
+            // using the default spec, don't modify additional arguments
+        } else {
+            QString parsedSpecOrginal = parsedSpec;
+            if (QFileInfo(parsedSpec).isRelative())
+                parsedSpec = QDir::cleanPath(directory + "/" + parsedSpec);
+            m_additionalArguments = Qt4Project::removeSpecFromArgumentList(m_additionalArguments);
+            if (parsedSpec != versionSpec) {
+                m_additionalArguments.prepend(parsedSpecOrginal);
+                m_additionalArguments.prepend("-spec");
+            }
+        }
     }
 
     // So now we have the version and the configuration for that version