What I expected to happen:
Edited textures on solid blocks would remain transparent except at far range, consistent with expected mipmap behavior.
What actually happened was:
There was no transparency up close, but the transparency returned after travelling a short distance from the blocks on screen. When up close, the transparency is rendered opaque as a matte color.
How to Reproduce:
Using the latest snapshot, download and use the attached resourcepack. In game, switch to Creative and place a block of Snow and a Block of Quartz. While looking at the blocks, fly away a short distance, about 20 blocks. To observe expected behavior, change to snapshot version 14w02b.