glb: ensure each super class processed once (IDEA-176779)

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/performance/LeastUpperBoundWithLotsOfSupers.java

@@ -0,0 +1,33 @@
+
+import java.util.List;
+import java.util.stream.Stream;
+
+class LeastUpperBoundTest {
+  void f(Stream<Klass> klasses) {
+    klasses.flatMap(d -> concat(Stream.of(d),
+                                d.getMethods().stream(),
+                                d.getMethods().stream()));
+  }
+
+  @SafeVarargs
+  private static <T> Stream<T> concat(Stream<? extends T>... streams) {
+    return null;
+  }
+}
+
+interface Node {}
+interface A<T extends Node> {}
+interface B<T extends Node> {}
+interface C<T extends Node> {}
+interface D<T extends Node> {}
+interface E<T extends Node> {}
+interface E1<T extends Node> {}
+interface E2<T extends Node> {}
+
+class Klass implements Node, A<Klass>, B<Klass>, C<Klass>, D<Klass>, E<Klass>, E1<Klass> {
+  public List<Method> getMethods() {
+    return null;
+  }
+}
+class Method implements Node, A<Method>, B<Method>, C<Method>, D<Method>, E<Method>, E1<Method> {}
+