[PATCH i-g-t 1/1] lib/igt_ktap: fix parsing problems for parametrized tests with no params

[Janusz Krzysztofik]

On Friday, 23 May 2025 10:35:44 CEST Jan Sokolowski wrote:
> In some cases, parametrized test might have no params and therefore no
> results to be reported, which causes parser failures.

Please add an excerpt from an error report and a related KTAP report from 
dmesg to your commit description for reference.

> 
> Add a condition that checks for that in the parser.
> 
> Signed-off-by: Jan Sokolowski <jan.sokolowski at intel.com>
> Suggested-by: Michal Wajdeczko <michal.wajdeczko at intel.com>

Please provide a reference to a real issue, if there is one tracked publicly.

> ---
>  lib/igt_ktap.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/lib/igt_ktap.c b/lib/igt_ktap.c
> index 300fb2bb5..34306a1a0 100644
> --- a/lib/igt_ktap.c
> +++ b/lib/igt_ktap.c
> @@ -250,6 +250,10 @@ int igt_ktap_parse(const char *buf, struct igt_ktap_results *ktap)
>  		return -EINPROGRESS;
>  	}
>  
> +	/* in case of parametrized test having no params and hence no results */
> +	if (igt_debug_on(ktap->expect == SUB_RESULT && code == IGT_EXIT_SKIP))
> +		ktap->expect = CASE_RESULT;

NAK.

That looks like you are trying to address a case when a test case opens a 
parametrized subtest section but returns no results from parametrized 
subtests.  If that case is now recognized by the parser as protocol violation 
while it should not, i.e., empty parametrized results section should be 
allowed, then that should be fixed in the input parser section, not in a next 
section that evaluates parsing results.

After the parser detects a KTAP parametrized test case header and a KTAP 
parametrized test case name, it shouldn't expect any parametrized subtest 
results like it does now but should just expect a test case result.  KTAP 
parametrized subtest result lines detected when the KTAP test case result line 
is expected should still be accepted.  Please find relevant steps in the 
parser code and fix them.  Then, as soon as the current requirement of at 
lease one result of a parametrised subtest expected is killed, the SUB_RESULT 
phase may be dropped from the list of parsing phases as no longer needed.

Please also add a corresponding test case, based on the now problematic KTAP 
output, to lib/tests/igt_ktap_parser.c

Thanks,
Janusz

> +
>  	/* neither a test case name nor result */
>  	if (ktap->expect != SUB_RESULT && code == IGT_EXIT_INVALID)
>  		return -EINPROGRESS;
>