[jvm] fix indexOf

[barisyild]

This commit resolves the error if the indexOf parameter is null.

Code

var value:String = "data";
trace(value.indexOf(null));

Exception

Exception in thread "main" java.lang.NullPointerException: Cannot invoke "String.coder()" because "str" is null
	at java.base/java.lang.String.indexOf(String.java:2593)
	at haxe.jvm.StringExt.indexOf(/usr/local/lib/haxe/std/jvm/StringExt.hx:51)
	at haxe.root.App.main(src/App.hx:36)
	at haxe.root.App.main(src/App.hx:1)

[Simn]

Could you add a test for this? I'm curious how other targets behave.

[flashultra]

I tested some targets ( https://try.haxe.org/#550C781c ) and the result was:
1) JS - return -1
2) Neko - ( Uncaught exception - Invalid field access : __s )
3) Eval - ( Uncaught exception Null Access )
4) Hashlink - ( Build failure )

Compiling native java code ( https://www.programiz.com/online-compiler/2pgIxccM3YmId ) will return "java.lang.NullPointerException:"

[barisyild]

I tested some targets ( https://try.haxe.org/#550C781c ) and the result was: 1) JS - return -1 2) Neko - ( Uncaught exception - Invalid field access : __s ) 3) Eval - ( Uncaught exception Null Access ) 4) Hashlink - ( Build failure )

Compiling native java code ( https://www.programiz.com/online-compiler/2pgIxccM3YmId ) will return "java.lang.NullPointerException:"

hxcpp target returns 0.
I think that's wrong, needs to fixed.

[tobil4sk]

This may be something better left unspecified

[Simn]

This may be something better left unspecified

Given the different results on each target, I agree. I'm leaving this open as a reminder to add a note to the API docs because that seems to be missing from the specification.

[barisyild]

This may be something better left unspecified

Given the different results on each target, I agree. I'm leaving this open as a reminder to add a note to the API docs because that seems to be missing from the specification.

I think this is a controversial issue and I think it should be discussed.

Haxe is very similar to JavaScript and I think it makes sense to return -1 on every target.