[PATCH v2] cmd: setexpr: fix no matching string in gsub return empty value

[Michal Simek]

HI,

čt 8. 2. 2024 v 16:00 odesílatel Massimiliano Minella
<massimiliano.minella at gmail.com> napsal:
>
> From: Massimiliano Minella <massimiliano.minella at se.com>
>
> In gsub, when the destination string is empty, the string 't' is
> provided and the regular expression doesn't match, then the final result
> is an empty string.
>
> Example:
>
> => echo ${foo}
>
> => setenv foo
> => setexpr foo gsub e a bar
> => echo ${foo}
>
> =>
>
> The variable ${foo} should contain "bar" and the lack of match shouldn't
> be considered an error.
>
> This patch fixes the erroneous behavior by removing the return
> statement and breaking out of the loop in case of lack of match.
>
> Also add a test for the no match case.
>
> Signed-off-by: Massimiliano Minella <massimiliano.minella at se.com>
> ---
> Changes in V2:
>  - update documentation to describe the behavior
>
>  cmd/setexpr.c             |  9 ++++-----
>  doc/usage/cmd/setexpr.rst |  1 +
>  test/cmd/setexpr.c        | 10 ++++++++++
>  3 files changed, 15 insertions(+), 5 deletions(-)
>
> diff --git a/cmd/setexpr.c b/cmd/setexpr.c
> index 233471f6cb..ab76824a32 100644
> --- a/cmd/setexpr.c
> +++ b/cmd/setexpr.c
> @@ -216,14 +216,12 @@ int setexpr_regex_sub(char *data, uint data_size, char *nbuf, uint nbuf_size,
>                 if (res == 0) {
>                         if (loop == 0) {
>                                 debug("%s: No match\n", data);
> -                               return 1;

This patch actually changed the return value from command.
In board/xilinx/zynqmp/zynqmp_kria.env we have

bootcmd=setenv model $board_name && if setexpr model gsub
.*$k24_starter* $k24_starter || setexpr model gsub .*$k26_starter*
$k26_starter; then run som_cc_boot; else run som_mmc_boot; run
som_cc_boot; fi

and this patch actually breaked it because we rely on return value.
Changing return value is not described and I want to know if this
patch should be fixed
or we should update our commands to match new return value.

Thanks,
Michal