SkriptParser incorrectly checks whether an expression in a pattern is nullable

[APickledWalrus]

Skript/Server Version

n/a

Bug Description

A user on discord reported this error:
ch.njol.skript.SkriptAPIException: The class 'object' does not provide a default expression. Either allow null (with %-object%) or make it mandatory [pattern: (execute|run) function <.+> [and store it in %~-objects%]]

This is because SkriptParser only checks the first character of the input to determine if the expression is nullable. It is not guaranteed to be the first character. Other areas of Skript (e.g. TypePatternElement) account for this.

Skript/src/main/java/ch/njol/skript/lang/SkriptParser.java

Line 245 in 7178dc4

if (!name.startsWith("-")) {

The best solution is likely to call getExprInfo and then just check whether the ExprInfo has it marked as nullable. This method does cache the input though so I'm not sure if that may be unwanted if the expression is nullable.

Expected Behavior

Skript should identify the expression as nullable and not print an error that it is does not allow null.

Steps to Reproduce

In a pattern, use a flag mask and then a nullable indicator, e.g. %~-objects%

Errors or Screenshots

full stacktrace: https://paste.gg/p/anonymous/fba5298c26b140198e1e7db93d410497

Other

No response

Agreement

• I have read the guidelines above and affirm I am following them with this report.