Improper macro expansion for instruction handler functions with a single expression

[Toshiyuki-Tega]

When defining a program module and instructions as follows

#[light_program]
#[program]
pub mod zktest {
    use super::*;

    pub fn compress01<'info>(
        ctx: LightContext<'_, '_, '_, 'info, Compress01<'info>>,
    ) -> Result<()> {
        ctx.light_accounts.compressed_user_record.user_authority = ctx.accounts.signer.key();
        Ok(())
    }

    // It doesn't work
    pub fn compress02<'info>(
        ctx: LightContext<'_, '_, '_, 'info, Compress02<'info>>,
    ) -> Result<()> {
        instructions::compress02(&mut ctx)
    }
}

the function body of compress02 is expanded like this:

        let mut ctx: ::light_sdk::context::LightContext<Compress02, LightCompress02> = ::light_sdk::context::LightContext::new(
            ctx,
            inputs,
            merkle_context,
            merkle_tree_root_index,
            address_merkle_context,
            address_merkle_tree_root_index,
        )?;
        let inputs = ParamsCompress02 {};
        ctx.check_constraints(&inputs)?;
        ctx.derive_address_seeds(address_merkle_context, &inputs);
        let ParamsCompress02 {} = inputs;
        ctx.verify(proof)?;
        instructions::compress02(&mut ctx)

and changes made to ctx in the instructions::compress02 function are not being reflected.

Current workaround is to assign the result into a temporary variable and return it.

    pub fn compress02<'info>(
        ctx: LightContext<'_, '_, '_, 'info, Compress02<'info>>,
    ) -> Result<()> {
        let retval = instructions::compress02(&mut ctx);
        retval
    }

[TUPM96]

Opened PR #2381 to fix this: #2381