17w14a doLimitedCrafting(true) Unable to repair tools/armor

Placing two items of the same type/grade into crafting box does not allow them to be repaired.

This is only observed with doLimitedCrafting(true)

Confirmed Singleplayer/Multiplayer

Discovered/Reported during the following Livestream. Evident around the 15min mark https://gaming.youtube.com/watch?v=GP-KANmtFM4