Re: Different behaviour when interpreting a here-document between 5.3 and 5.5.1

[Enrico Maria Crisostomo <enrico.m.crisostomo@xxxxxxxxx>]

> On 19 Apr 2018, at 23:52, Enrico Maria Crisostomo <enrico.m.crisostomo@xxxxxxxxx> wrote:
> 
> Hi,
> 
> I'm struggling with an apparently simple problem.  A script of mine has a function that writes a here-document whose lines end with a backslash.  The script has been working fine until zsh has been updated recently.
> 
> The relevant part of the code is the following
> 
>  mp_calculate_checksums()
>  {
>    cat <<EOF
>  checksums           rmd160 ${CHECKSUM_RMD160} \\
>                      sha256 ${CHECKSUM_SHA256} \\
>                      size   ${CHECKSUM_SIZE}
>  EOF
>  }
> 
> The expected output is something like:
> 
>  checksums           rmd160 281d97a37125fca07ff81a72ac337f6a23f5d2b0 \
>                      sha256 233cd8724fd95e10b82ed62c692e7e79cca9114b49be834e65cd05b529d8ba70 \
>                      size   31
> 
> When running the same script on 5.5.1, I get a single line of output, as if the last backslash of \\ were escaping the newline.
> 
>  checksums           rmd160 281d97a37125fca07ff81a72ac337f6a23f5d2b0 \                    sha256 233cd8724fd95e10b82ed62c692e7e79cca9114b49be834e65cd05b529d8ba70 \                    size   31
> 
> I haven't been able to troubleshoot it so far, and the zsh documentation seems to imply that the correct behaviour is the former, not the latter.
> 
> Thanks in advance for you help,
> -- 
> Enrico

Thanks for your answer, Bart.  Apologies for manually quoting it, but I haven't received a mail from the mailing list, so I can't reply:

> Yeah, this is commit 47aa6095 aka workers/42355.  It's recognizing
> backslash-newline but not whether the backslash is itself escaped.
> 
> The NEWS file should have mentioned the change to here-documents, I
> think.  However, not catching the double backslash is a bug.  However,
> part 2, figuring this out requires scanning backwards to see if you
> have an even or odd number of trailing backlashes, or scanning forward
> and tokenizing while consuming the document.  Bleah.

Should I file a bug report, write to zsh-workers, or do something else?  Or may I consider that your answering the mail is equivalent to a bug having been open?

Thanks,
-- 
Enrico