JsonPrimitive#equals Method behaves incorrect when used with BigInteger

[noeppi-noeppi]

Gson version

2.9.0

Java / Android version

Eclipse Adoptium OpenJDK 64-Bit Server VM 17.0.2+8 on Linux

Used tools

• Maven; version:
• Gradle; version: 7.3.3
• ProGuard (attach the configuration file please); version:
• ...

Description

Two JsonPrimitives with BigInteger values return true from their equals method if their long value obtained from Number#longValue is equal. This for example causes the numbers 23648748948963264236478263434 and 808933803388026932016705674 to be considered equal.

This is because both numbers are greater than Long.MAX_VALUE, so only the least significant 64 bits of these numbers are considered in the longValue() method. These happen to be 6484271001536295050 for both of the numbers, so JsonPrimitive considers them equal.

Expected behaviour

The expected behaviour is that JsonPrimitive#equals returns false for values which don't actually equal each other.

Actual behaviour

The actual behaviour is that JsonPrimitive#equals returns true for BigIntegers whose 64 least significant bits are the same.

Reproduction steps

JsonPrimitive p1 = new JsonPrimitive(new BigInteger("23648748948963264236478263434"));
JsonPrimitive p2 = new JsonPrimitive(new BigInteger("808933803388026932016705674"));
System.out.println(Objects.equals(p1, p2)); // is true, should be false

Exception stack trace

No exception occurred.

[Marcono1234]

Seems to be related to #904

[MaicolAntali]

This issue can be closed. Related PR: #2311

[Marcono1234]

@MaicolAntali, thanks! The reproduction steps provided above print false now, as expected.