Dead code in toast_fetch_datum_slice?

[Stephen Frost]

Greetings,

Perhaps I'm missing something, but in toast_fetch_datum_slice() there's:

        Assert(!VARATT_EXTERNAL_IS_COMPRESSED(toast_pointer));

Followed, not long after, by:

    if (VARATT_EXTERNAL_IS_COMPRESSED(toast_pointer))
        SET_VARSIZE_COMPRESSED(result, length + VARHDRSZ);
    else
        SET_VARSIZE(result, length + VARHDRSZ);

Further, the only caller of this function today is
heap_tuple_untoast_attr_slice(), which does:

    /* fast path for non-compressed external datums */
    if (!VARATT_EXTERNAL_IS_COMPRESSED(toast_pointer))
        return toast_fetch_datum_slice(attr, sliceoffset, slicelength);

As such, I'm feeling like that conditional to handle the case where this
function is passed a compressed TOAST value is rather confusing dead
code.

Hence I'm proposing the attached.

Thoughts?

Thanks!

Stephen

diff --git a/src/backend/access/heap/tuptoaster.c b/src/backend/access/heap/tuptoaster.c
new file mode 100644
index fdbaf38..9a63723
*** a/src/backend/access/heap/tuptoaster.c
--- b/src/backend/access/heap/tuptoaster.c
*************** toast_fetch_datum_slice(struct varlena *
*** 2085,2094 ****
  
  	result = (struct varlena *) palloc(length + VARHDRSZ);
  
! 	if (VARATT_EXTERNAL_IS_COMPRESSED(toast_pointer))
! 		SET_VARSIZE_COMPRESSED(result, length + VARHDRSZ);
! 	else
! 		SET_VARSIZE(result, length + VARHDRSZ);
  
  	if (length == 0)
  		return result;			/* Can save a lot of work at this point! */
--- 2085,2091 ----
  
  	result = (struct varlena *) palloc(length + VARHDRSZ);
  
! 	SET_VARSIZE(result, length + VARHDRSZ);
  
  	if (length == 0)
  		return result;			/* Can save a lot of work at this point! */

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