Compiler crash (& first draft of a Regex patch)

[Ben Evans]

Hi,

This block of code, when added to java.util.regex.Pattern, causes an
NPE in the compiler:

    public Predicate<String> asPredicate(){
        return s -> this.matcher(s).find();
    }

    public <T extends CharSequence> Stream<CharSequence>
splitAsStream(T input) {
		class CharSeqIterator implements Iterator<CharSequence> {
			int cur = 0; // Position in the input string
			Matcher curMatcher = null;

	        public boolean hasNext() {
				// true iff we match on the remaining substring
				if (curMatcher == null)
					curMatcher = Pattern.this.matcher(input.subSequence(cur, input.length()));
				return curMatcher.find();
	        }

	        public CharSequence next() {
	            if (hasNext()) {
					CharSequence tmpCs = input.subSequence(cur, curMatcher.start() - 1);
					cur = curMatcher.end();
					curMatcher = null;
	                return tmpCs;
				} else {
	                throw new NoSuchElementException();		
				}
	        }

	        public void forEach(java.util.function.Block<? super
CharSequence> block) {
				while (cur < input.length()) {
	                block.accept(next());
	            }
	        }
		}
	
		return Streams.stream(() -> Streams.spliteratorUnknownSize(new
CharSeqIterator()), StreamOpFlag.IS_ORDERED);
    }

An exception has occurred in the compiler (1.8.0-internal). Please
file a bug at the Java Developer Connection
(http://java.sun.com/webapps/bugreport)  after checking the Bug Parade
for duplicates. Include your program and the following diagnostic in
your report.  Thank you.
java.lang.NullPointerException
	at com.sun.tools.javac.jvm.Code.emitop0(Code.java:540)
	at com.sun.tools.javac.jvm.Items$LocalItem.load(Items.java:397)
	at com.sun.tools.javac.jvm.Gen.genArgs(Gen.java:911)
	at com.sun.tools.javac.jvm.Gen.visitNewClass(Gen.java:1788)
	at com.sun.tools.javac.tree.JCTree$JCNewClass.accept(JCTree.java:1462)
	at com.sun.tools.javac.jvm.Gen.genExpr(Gen.java:892)
	at com.sun.tools.javac.jvm.Gen.genArgs(Gen.java:911)
	at com.sun.tools.javac.jvm.Gen.visitApply(Gen.java:1745)
	at com.sun.tools.javac.tree.JCTree$JCMethodInvocation.accept(JCTree.java:1410)
	at com.sun.tools.javac.jvm.Gen.genExpr(Gen.java:892)
	at com.sun.tools.javac.jvm.Gen.visitReturn(Gen.java:1714)
	at com.sun.tools.javac.tree.JCTree$JCReturn.accept(JCTree.java:1328)
	at com.sun.tools.javac.jvm.Gen.genDef(Gen.java:682)
	at com.sun.tools.javac.jvm.Gen.genStat(Gen.java:717)
	at com.sun.tools.javac.jvm.Gen.genStat(Gen.java:703)
	at com.sun.tools.javac.jvm.Gen.genStats(Gen.java:754)
	at com.sun.tools.javac.jvm.Gen.visitBlock(Gen.java:1089)
	at com.sun.tools.javac.tree.JCTree$JCBlock.accept(JCTree.java:852)
	at com.sun.tools.javac.jvm.Gen.genDef(Gen.java:682)
	at com.sun.tools.javac.jvm.Gen.genStat(Gen.java:717)
	at com.sun.tools.javac.jvm.Gen.genMethod(Gen.java:967)
	at com.sun.tools.javac.jvm.Gen.visitMethodDef(Gen.java:940)
	at com.sun.tools.javac.tree.JCTree$JCMethodDecl.accept(JCTree.java:736)
	at com.sun.tools.javac.jvm.Gen.genDef(Gen.java:682)
	at com.sun.tools.javac.jvm.Gen.genClass(Gen.java:2309)
	at com.sun.tools.javac.main.JavaCompiler.genCode(JavaCompiler.java:752)
	at com.sun.tools.javac.main.JavaCompiler.generate(JavaCompiler.java:1522)
	at com.sun.tools.javac.main.JavaCompiler.generate(JavaCompiler.java:1486)
	at com.sun.tools.javac.main.JavaCompiler.compile2(JavaCompiler.java:908)
	at com.sun.tools.javac.main.JavaCompiler.compile(JavaCompiler.java:867)
	at com.sun.tools.javac.main.Main.compile(Main.java:482)
	at com.sun.tools.javac.main.Main.compile(Main.java:363)
	at com.sun.tools.javac.main.Main.compile(Main.java:352)
	at com.sun.tools.javac.main.Main.compile(Main.java:343)
	at com.sun.tools.javac.Main.compile(Main.java:76)
	at com.sun.tools.javac.Main.main(Main.java:61)

Comments on the approach I'm taking in the patch also very welcome. I
haven't actually got this to build successfully yet, so haven't been
able to test it.

Thanks,

Ben