[Emissive textures] Emissive feature doesn't work on string?

[Baby-FarkMcGeezax]

I tried making an emissive texture for the tripwire string, but it doesn't work. Emissive itself isn't broken, the tripwire hooks are affected (see image). I haven't found any other blocks that are affected (although I of course haven't tested every single one)

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OptiFine HD U I9 pre1