Comment 1:

Do you think this is a documentation error or a code error?

Labels changed: added repo-main, release-go1.4.

Comment 2:

My guess is this is a documentation error, as this is the only place ErrDictionary could
be returned.
From the perspective of a user, I'd also want it to return an error for a wrong
dictionary. Dictionary is not a hint but mandatory; one need to give exactly the same
dictionary to inflate and deflate, or otherwise zlib will fail to decompress it.

Comment 3:

Thanks.  Looking deeper, I think the comment is actually arguably correct.  It says
"NewReaderDict ignores the dictionary if the compressed data does not refer to it." 
What it means by that, I think, is that if the FDICT flag is not set (z.scratch[1]&0x20
== 0) the dict argument is correct.

Comment 4:

That interpretation makes sense, but it's I believe confusing. Maybe we should refine
the document?

Comment 5:

SGTM but I'll let somebody else sort this out.

Comment 6:

Labels changed: added documentation.

Owner changed to @rsc.

Status changed to Accepted.

Comment 7:

I think this is user error but I will add a sentence anyway.

Comment 8:

CL https://golang.org/cl/147390043 mentions this issue.

Comment 9:

This issue was closed by revision 0239595.

Status changed to Fixed.