use-native-decoding=true does not work when combined with function composition

[carolmorneau]

Description
use-native-decoding=true works as expected when there is no function composition. The skipInputConversion flag in SimpleFunctionRegistry is properly set and payload conversion is not attempted.

However, if function composition is used in combination with use-native-encoding=true, the skipInputConversion flag is always false and payload conversion is attempted.

To Reproduce
Using this sample project which is based on the function-composition-rabbit sample

• Run the sample with the issue2945 profile
• Send some data to the RabbitMQ exchange (at least 3 messages since batch-size=3)
• Notice that an exception is thrown from JsonMessageConverter; however, we would expect skipInputConversion=true and converters to not be called.

Expected behavior

I would expect the framework to not attempt payload conversion when use-native-decoding=true

[olegz]

i will transfer this to spring-cloud-function

[olegz]

We need to ensure that if setSkipInputConversion is set on a function then even if this function is composed from multiple functions the settings propagates to all of them

[carolmorneau]

Thank you @olegz
It was not my main focus but I believe the same issue takes place for the producer property use-native-encoding=true.

Thank you

[carolmorneau]

I retested with 4.1.2-SNAPSHOT and this issue appears to be fixed. Thank you @olegz