inference variables: ensure variable is not mixed with type parameter for recursive calls (IDEA-147639)

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/graphInference/RecursiveCallsWithNestedInference.java

@@ -0,0 +1,35 @@
+import java.util.*;
+import java.util.stream.Collectors;
+
+class Test {
+  private <S> List<S> bar(List<S> list) {
+    return null;
+  }
+
+  private <E> List<List<E>> foo(List<E> l) {
+    foo(bar(l));
+    final List<List<Object>> perms = foo(null);
+    return null;
+  }
+
+  public static <E> List<E> pipe(E head, List<E> tail) {
+    List<E> newList = new ArrayList<>(tail);
+    newList.add(0, head);
+    return newList;
+  }
+  public static <E> List<E> subtract(List<E> list, E e) {
+    List<E> newList = new ArrayList<>(list);
+    newList.remove(e);
+    return newList;
+  }
+  public static <E> List<List<E>> perms(List<E> l) {
+    return l.isEmpty()
+           ? Collections.singletonList(Collections.emptyList())
+           : l.stream().flatMap(h -> perms(subtract(l, h)).stream()
+             .map(t -> pipe(h, t))).collect(Collectors.toList());
+  }
+
+  public static void main(String[] args) {
+    System.out.println(perms(Arrays.asList("a", "b", "c")));
+  }
+}