[Fontconfig] Config Parsing Error Reporting (was Re: Another proposal for saving custom fonts in fontconfig)

[Lawrence D'Oliveiro]

On Thu, 4 Jul 2019 17:49:43 +0900, Akira TAGOH wrote:

> On Thu, Jul 4, 2019 at 8:05 AM Lawrence D'Oliveiro
> <ldo at geek-central.gen.nz> wrote:
>>
>> Speaking of which, it would be good if there was an
>> alternative to FcConfigParseAndLoad which could return a useful
>> status code from parsing a config file, instead of only printing
>> out errors.
>>
> That should be a bug. please file an issue.

The man page for FcConfigParseAndLoad says

    Error and warning messages will be output to stderr.  Returns
    FcFalse if some error occurred while loading the file, either a
    parse error, semantic error or allocation failure. Otherwise
    returns FcTrue.

So it is a documented “feature” that errors and warnings are output to
stderr. But as far as I recall, it does not return FcFalse if parsing
problems were encountered (only if the config file could not be found),
so that much is a bug. It would be nice to have an API call that
returned the error indications to the caller; perhaps via a callback for
each error found.