Provision previously only checked for a single opening brace at the
start of a destination, so values like {result}suffix, {result, and
{result}} passed validation. strings.Trim(dest, "{}") then silently
stored a wrong placeholder name (e.g. result}suffix), making the
intended value unavailable.
Require the destination to be exactly one placeholder: a single
opening brace at the start, a single closing brace at the end, and a
non-empty name.
Fixes#8073
It was not accurate. Placeholders could be used in outputs that are
defined in the same mapping as long as that placeholder does not do the
same.
A more general solution would be to detect it at run-time in the
replacer directly, but that's a bit tedious
and will require allocations I think.
A better implementation of this check could still be done, but I don't
know if it would always be accurate. Could be a "best-effort" thing?
But I've also never heard of an actual case where someone configured
infinite recursion...
* caddyfile: Support for raw token values, improve `map`, `expression`
* Applied code review comments
* Rename RawVal to ValRaw
Co-authored-by: Matthew Holt <mholt@users.noreply.github.com>
gelsomino