On Sun, Feb 18, 2024, at 5:03 PM, Kerin Millar wrote: > Hi, > > This report stems from the discussion at > https://lists.gnu.org/archive/html/help-bash/2024-02/msg00085.html. > > Consider the following two cases. > > $ ( set a -- b; f=+ IFS=$f; [[ $f$*$f == *"$f--$f"* ]]; echo $? ) > 0 > > $ ( set a -- b; f=$'\1' IFS=$f; [[ $f$*$f == *"$f--$f"* ]]; echo $? ) > 1 > > It does not make sense that that the exit status value differs between > these cases, especially since SOH is not a whitespace character (in the > sense of field splitting). I think that the second case should also > yield 0. Regardless of what the intended behaviour is, I would also > expect for the manual to describe it. > > Note that quoting the left-hand side fixes it for SOH. In the absence > of quotes, xtrace output suggests that all of the SOH characters are > stripped from the expansion of $f$*$f. > > $ ( set a -- b; f=$'\1' IFS=$f; [[ "$f$*$f" == *"$f--$f"* ]]; echo $? ) > 0
Case commands exhibit similar behavior: $ set a -- b $ (f=+ IFS=$f; case $* in *"$f"*) echo 0;; *) echo 1;; esac) 0 $ (f=$'\1' IFS=$f; case $* in *"$f"*) echo 0;; *) echo 1;; esac) 1 $ (f=$'\1' IFS=$f; case "$*" in *"$f"*) echo 0;; *) echo 1;; esac) 0 -- vq
