Compiler NPE in local-methods branch with recursive lambda

[Jake Wharton]

With hg revision 4a43a5fc2c4a, given the following pared-down input:

interface Node {
  List<Node> getNodes();

  static boolean any(Node root, Predicate<Node> predicate) {
    boolean hasMatch(Node node) {
      return node.getNodes().stream().anyMatch(n -> hasMatch(n));
    }
    return hasMatch(root);
  }
}

Compilation causes:

java.lang.NullPointerException
at jdk.compiler/com.sun.tools.javac.jvm.Code.emitop0(Code.java:570)
at jdk.compiler/com.sun.tools.javac.jvm.Items$LocalItem.load(Items.java:399)
at jdk.compiler/com.sun.tools.javac.jvm.Gen.genArgs(Gen.java:885)
at jdk.compiler/com.sun.tools.javac.jvm.Gen.visitApply(Gen.java:1851)
at
jdk.compiler/com.sun.tools.javac.tree.JCTree$JCMethodInvocation.accept(JCTree.java:1736)
at jdk.compiler/com.sun.tools.javac.jvm.Gen.genExpr(Gen.java:860)
at jdk.compiler/com.sun.tools.javac.jvm.Gen.visitReturn(Gen.java:1814)
at
jdk.compiler/com.sun.tools.javac.tree.JCTree$JCReturn.accept(JCTree.java:1648)
at jdk.compiler/com.sun.tools.javac.jvm.Gen.genDef(Gen.java:597)
at jdk.compiler/com.sun.tools.javac.jvm.Gen.genStat(Gen.java:632)
at jdk.compiler/com.sun.tools.javac.jvm.Gen.genStat(Gen.java:618)
at jdk.compiler/com.sun.tools.javac.jvm.Gen.genStats(Gen.java:669)
at jdk.compiler/com.sun.tools.javac.jvm.Gen.visitBlock(Gen.java:1080)
at
jdk.compiler/com.sun.tools.javac.tree.JCTree$JCBlock.accept(JCTree.java:1029)
at jdk.compiler/com.sun.tools.javac.jvm.Gen.genDef(Gen.java:597)
at jdk.compiler/com.sun.tools.javac.jvm.Gen.genStat(Gen.java:632)
at jdk.compiler/com.sun.tools.javac.jvm.Gen.genMethod(Gen.java:950)
at jdk.compiler/com.sun.tools.javac.jvm.Gen.visitMethodDef(Gen.java:913)
at
jdk.compiler/com.sun.tools.javac.tree.JCTree$JCMethodDecl.accept(JCTree.java:875)
at jdk.compiler/com.sun.tools.javac.jvm.Gen.genDef(Gen.java:597)
at jdk.compiler/com.sun.tools.javac.jvm.Gen.genClass(Gen.java:2391)
at
jdk.compiler/com.sun.tools.javac.main.JavaCompiler.genCode(JavaCompiler.java:757)
at
jdk.compiler/com.sun.tools.javac.main.JavaCompiler.generate(JavaCompiler.java:1677)
at
jdk.compiler/com.sun.tools.javac.main.JavaCompiler.generate(JavaCompiler.java:1645)
at
jdk.compiler/com.sun.tools.javac.main.JavaCompiler.compile(JavaCompiler.java:973)
at jdk.compiler/com.sun.tools.javac.main.Main.compile(Main.java:318)
at jdk.compiler/com.sun.tools.javac.main.Main.compile(Main.java:176)
at jdk.compiler/com.sun.tools.javac.Main.compile(Main.java:57)
at jdk.compiler/com.sun.tools.javac.Main.main(Main.java:43)

The problem seems to be a combination of the fact that the local method
captures 'predicate' and recursively invokes itself from a lambda. Removing
the 'if' will result in successful compilation. Replacing the stream with a
for-each will result in successful compilation.