Incompatibility between @Spy annotation and java.util.Properties in OpenJDK17

[pgrt]

Hello,

I am the Debian maintainer of owner. In Debian unstable with OpenJDK 17.0.5 and mockito 2.23.0, I get

[ERROR] testListPrintStream(org.aeonbits.owner.PropertiesInvocationHandlerTest) Time elapsed: 0.542 s <<< ERROR!
java.lang.NullPointerException: Cannot invoke "java.util.concurrent.ConcurrentHashMap.putAll(java.util.Map)" because "this.map" is null
at org.aeonbits.owner.PropertiesInvocationHandlerTest.before(PropertiesInvocationHandlerTest.java:46)

[ERROR] testListPrintWriter(org.aeonbits.owner.PropertiesInvocationHandlerTest) Time elapsed: 0.002 s <<< ERROR!
java.lang.NullPointerException: Cannot invoke "java.util.concurrent.ConcurrentHashMap.putAll(java.util.Map)" because "this.map" is null
at org.aeonbits.owner.PropertiesInvocationHandlerTest.before(PropertiesInvocationHandlerTest.java:46)

Interestingly, it seems there is an issue with properties in the before method being declared with the @SPY annotation. Indeed, changing slightly the test file to the enclosed one (see lines 31, 32, 46, 47) causes an error on line 46 but not on line 47.
PropertiesInvocationHandlerTest.java.txt

Honestly I cannot explain what causes this, but if you can then I am interested in knowing.

Bye,
Pierre