PsiElement.getProject() won't fail with NPE anymore even if element is invalid. null will be returned instead.

source/com/intellij/psi/impl/PsiElementBase.java

@@ -125,7 +125,8 @@ public abstract class PsiElementBase extends ElementBase implements PsiElement,N
   }
 
   public Project getProject() {
-    return getManager().getProject();
+    final PsiManager manager = getManager();
+    return manager != null ? manager.getProject() : null;
   }
 
   public Language getLanguage() {

source/com/intellij/psi/impl/source/tree/CompositePsiElement.java

@@ -237,7 +237,8 @@ public abstract class CompositePsiElement extends CompositeElement implements Ps
   }
 
   public Project getProject() {
-    return getManager().getProject();
+    final PsiManager manager = getManager();
+    return manager != null ? manager.getProject() : null;
   }
 
   public Language getLanguage() {

source/com/intellij/psi/impl/source/tree/LeafPsiElement.java

@@ -184,7 +184,8 @@ public class LeafPsiElement extends LeafElementImpl implements PsiElement {
   }
 
   public Project getProject() {
-    return getManager().getProject();
+    final PsiManager manager = getManager();
+    return manager != null ? manager.getProject() : null;
   }
 
   public Language getLanguage() {