On 9/13/20 8:21 AM, Andreas Schwab wrote:
> On Sep 10 2020, Chet Ramey wrote:
>
>> qqq. Fixed a bug that could cause backslashes quoting double quotes in here
>> document bodies to not be removed when expanding the body.
>
> Are you sure about this? My reading of POSIX says that a backslash
> before a double quote should not be removed, as double quotes are not
> special in here docs.
The specific construct is
P=A
cat <<EOF
${P+\"$P\"}
EOF
from https://lists.gnu.org/archive/html/bug-bash/2019-01/msg00193.html .
In this case, the usual proscription on double quotes in here-documents
does not apply, since the double quote appears within ${}.
This change makes the above and
echo "${P+\"$P\"}"
echo the same thing.
The bash-5.1 behavior is consistent with what other shells claiming POSIX
conformance, except the BSD ash-based shells, produce. There's pretty wide
variance in behavior between shells with all of the variants of putting a
double quote inside a parameter expansion inside a here-document, and
POSIX has basically thrown its hands in the air in disgust.
--
``The lyf so short, the craft so long to lerne.'' - Chaucer
``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU [email protected] http://tiswww.cwru.edu/~chet/
