The Bug: 

When using the /summon command to summon vines, the texture does not appear, but you are still able to climb on them.

(Not a duplicate of Anthony Cicinelli's report).

Reproduce:

Place a block of any type on the ground.

2. Break the block and grab the coordinates of where the block just was.

3. Place the block back.

4. Type /setblock ~ ~ ~ vine (Replace the ~'s to the placed block's coordinates.

5. Done