[PROPOSAL] New Get() API for the Txn error body

[Leif Hedstrom]

We have an existing API to set the error body (TSHttpTxnErrorBodyGet() ), and 
I’d like to add the corresponding Get’er for this. I’m proposing the following:

    /**
      Retrives the error body, if any, from a transaction. This would be a body 
as set
      via the API body.

      @param txnp HTTP transaction whose parent proxy to get.
      @param buflength Optional output pointer to the length of the body 
message.
      @param mimetype Optional output pointer to the MIME type of the response.
    */
    char *TSHttpTxnErrorBodyGet(TSHttpTxn txnp, size_t *buflength, char 
**mimetype);



The buflength and mimetype are pointers (output), which can be nullptr’s. If 
they are provided, the length and/or mimetype pointer as set using the 
TSHttpTxnErrorBodyGet() is also returned. The return value is the body string.


This new API would return a nullptr if no error body has been set via the 
TSHttpTxnErrorBodySet() API.

Cheers,

— Leif

Thanks to Jasmine Emanuoel for some great ideas around how to use these APIs 
together with HTTP Txn errors.