Re: [PATCH] Fix leaked internal escapes of patsub_replacement ${var/$pat/"&"} with pat=# or pat=%

[Chet Ramey]

On 7/18/22 2:11 AM, Koichi Murase wrote:
> Here is another patch that was pending.
>
> Bash Version: 5.2
> Commit 87a6e89edc7cb1af057e2c15666df189595d305b (the current devel)
>
> Description:
>
>    When `shopt -s patsub_replacement' is turned on and the pattern
>    string `pat' of ${var/$pat/"&"} is just an anchoring character `#'
>    or `%', the internal escape of `&' (i.e., `\&') remains in the
>    result of the parameter expansion.  Also, with the same condition,
>    the unquoted & in ${var/$pat/&} remains a literal & where we expect
>    it to be expanded to an empty string.

Thanks for the patch. I think this is reasonable; it duplicates what `sed'
does when presented with a BRE like '^' or '$', or when it gets a null
input line. I'll put this in for 5.2-rc2.

Chet

--
``The lyf so short, the craft so long to lerne.'' - Chaucer
                 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU    chet@case.edu    http://tiswww.cwru.edu/~chet/