fix possible npe in TagReference of php Haehnchen#331

Author: Haehnchen

src/fr/adrienbrault/idea/symfony2plugin/util/dict/ServiceUtil.java

@@ -17,7 +17,6 @@
 import fr.adrienbrault.idea.symfony2plugin.stubs.indexes.ContainerParameterStubIndex;
 import fr.adrienbrault.idea.symfony2plugin.stubs.indexes.ServicesTagStubIndex;
 import fr.adrienbrault.idea.symfony2plugin.util.PhpElementsUtil;
-import fr.adrienbrault.idea.symfony2plugin.util.PsiElementUtils;
 import fr.adrienbrault.idea.symfony2plugin.util.service.ServiceXmlParserFactory;
 import org.apache.commons.lang.StringUtils;
 import org.jetbrains.annotations.Nullable;
@@ -167,7 +166,10 @@ public static Collection<PhpClass> getTaggedClassesWithCompiled(Project project,
 
  for(String className: taggedCompiledClasses) {
  if(!uniqueClass.contains(className)) {
- taggedClasses.add(PhpElementsUtil.getClass(project, className));
+ PhpClass phpClass = PhpElementsUtil.getClass(project, className);
+ if(phpClass != null) {
+ taggedClasses.add(phpClass);
+ }
  }
  }