The bug

The way in which the dragon egg texture is applied to the north, east, south and west faces of the block is very strange.

This, like MC-120417, appears to have originated as a result of dragon eggs being converted to json models in release 1.8, and persisted due to how strange the dragon egg texture is.

How to reproduce

Two resource packs are attached to this issue: one for use in release 1.7.10 and release 1.8, and another for use in the current version.

1. Download both resource packs
2. Load up version 1.7.10
3. Obtain a dragon egg (you'll probably need commands due to MC-55718)
4. Apply the "old" resource pack
5. Inspect each side of the block
6. Load up that same world in release 1.8
7. Inspect the dragon egg again, while still using the resource pack
8. Load up the latest version as of reading
9. Apply the "new" resource pack
10. Obtain a dragon egg and inspect it

Expected results

The side textures of the dragon eggs would be mapped in a way that makes sense.

Actual results

The side textures are mapped in a way that makes sense in 1.7.10. However, in 1.8 and the latest version, they are mapped seemingly randomly.

How to fix

A resource pack that completely fixes this issue is attached to this ticket, which also fixes MC-120417 and MC-199238. This model is based off of the 1.7.10 dragon egg model and therefore has the same mapping as it (with the exception of the bottom face - it was mirrored in 1.7.10, but is mapped normally in this fix). It also only uses 33 texture planes instead of vanilla's 48, so should be considerably better for performance. Also included in the resource pack is a version of the dragon egg texture which eliminates all pixels the model does not use.

I give Mojang my full permission and strong encouragement to replace vanilla's current dragon egg model with the version provided in the fix resource pack for the benefit of texture pack creators and the like worldwide. Likewise for the dragon egg texture without the unused pixels.