null check in getSourceParser(IProject project, String natureId)
diff --git a/core/plugins/org.eclipse.dltk.core/ast/org/eclipse/dltk/ast/parser/SourceParserManager.java b/core/plugins/org.eclipse.dltk.core/ast/org/eclipse/dltk/ast/parser/SourceParserManager.java
index 7612fe9..18e9b3f 100644
--- a/core/plugins/org.eclipse.dltk.core/ast/org/eclipse/dltk/ast/parser/SourceParserManager.java
+++ b/core/plugins/org.eclipse.dltk.core/ast/org/eclipse/dltk/ast/parser/SourceParserManager.java
@@ -77,7 +77,12 @@
 	}
 
 	public ISourceParser getSourceParser(IProject project, String natureId) {
-		return ((SourceParserContribution) getSelectedContribution(project, natureId)).getSourceParser();
+		SourceParserContribution contribution = (SourceParserContribution) getSelectedContribution(
+				project, natureId);
+		if (contribution != null) {
+			return contribution.getSourceParser();
+		}
+		return null;
 	}
 	
 	static class SourceParserContribution extends DLTKContributedExtension {