busybox/shell/hush_test
Denys Vlasenko eb54ca8be0 ash: expand: Do not quote backslashes in unquoted parameter expansion
Upstream commit:

    Date: Wed, 28 Mar 2018 18:37:51 +0800
    expand: Do not quote backslashes in unquoted parameter expansion

    Here is a better example:

        a="/*/\nullx" b="/*/\null"; printf "%s\n" $a $b

    dash currently prints

        /*/\nullx
        /*/\null

    bash prints

        /*/\nullx
        /dev/null

    You may argue the bash behaviour is inconsistent but it actually
    makes sense.  What happens is that quote removal only applies to
    the original token as seen by the shell.  It is never applied to
    the result of parameter expansion.

    Now you may ask why on earth does the second line say "/dev/null"
    instead of "/dev/\null".  Well that's because it is not the quote
    removal step that removed the backslash, but the pathname expansion.

    The fact that the /de\v does not become /dev even though it exists
    is just the result of the optimisation to avoid unnecessarily
        calling stat(2).  I have checked POSIX and I don't see anything
    that forbids this behaviour.

    So going back to dash yes I think we should adopt the bash behaviour
    for pathname expansion and keep the existing case semantics.

    This patch does exactly that.  Note that this patch does not work
    unless you have already applied

        https://patchwork.kernel.org/patch/10306507/

    because otherwise the optimisation mentioned above does not get
    detected correctly and we will end up doing quote removal twice.

    This patch also updates expmeta to handle naked backslashes at
    the end of the pattern which is now possible.

    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

function                                             old     new   delta
expmeta                                              618     653     +35
memtodest                                            146     147      +1

Tested to work with both ASH_INTERNAL_GLOB on and off.

hush does not handle this correctly.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2018-08-07 18:58:02 +02:00
..
hush-arith ash: parser: Add syntax stack for recursive parsing 2018-04-02 13:15:37 +02:00
hush-bugs
hush-getopts
hush-glob ash: expand: Do not quote backslashes in unquoted parameter expansion 2018-08-07 18:58:02 +02:00
hush-heredoc hush: add "heredoc.tests" from ash, tweak ash "is a function" message 2018-07-24 17:10:18 +02:00
hush-invert
hush-leak
hush-misc ash: eval: Variable assignments on functions are no longer persistent 2018-08-05 11:14:11 +02:00
hush-parsing hush: fix recent breakage from parse_stream() changes 2018-04-11 20:00:43 +02:00
hush-psubst hush: fix a few more corner cases with empty-expanding cmds 2018-04-05 15:15:53 +02:00
hush-quoting hush: adopt ash's quote_in_varexp1.tests 2018-08-05 20:03:04 +02:00
hush-read hush: fix IFS handling in read 2018-04-11 17:18:34 +02:00
hush-redir hush: fix nested redirects colliding with script fds 2018-07-24 16:54:41 +02:00
hush-signals
hush-standalone
hush-vars ash: expand: Fix ghost fields with unquoted $@/$* 2018-08-05 14:29:58 +02:00
hush-z_slow hush: improve ${var#...}, ${var:+...} and ${var/.../...} - handle quoting 2018-07-17 14:21:38 +02:00
.gitignore
run-all