[MC-262117] Language regex too broad

Language.UNSUPPORTED_FORMAT_PATTERN is intended to catch stray %d and %f placeholders in the translation resources and convert them to %s, since the translation component only supports this.

However, the regex is currently too broad – in particular it will also catch and convert %%dark and %%food (to %%sark and %%sood respectively), despite these being escaped.

This does not directly affect players, but it's a landmine waiting for mod developers and also your own dev team.

Comments 3

user-f2760 2023-04-26T11:41:23Z

Affects resource packs in vanilla as well.

Simply fixed by checking if it's escaped or not, or by simply removing the converting since it has been deprecated for a ton of versions and vanilla is entirely converted.

SkyEye_FAST 2024-08-05T09:12:56Z

Still exists in 1.21. Any content matching the following pattern will be replaced.

%(\d+\$)?[\d.]*[df]

Gavin Lambert 2026-01-12T09:10:44Z

Actually it looks like it’s worse in 1.21.1 (possibly earlier, didn’t check when it changed). When the regex matches it will now replace with “%$1s” instead of “%s”, which is both illegal syntax and had it been the right syntax would mess up the argument ordering.