Tab completing doesn't work properly with execute

After typing: "/execute @p ~ ~ ~ /tp @e[type=Villager,c=1] ", I pressed tab and expected it to place my name there, as it would when using /tp without execute, but it didn't. This seems to happen with any other command in an execute command as well.

What I expected to happen:
tab completion would work properly with execute.

What actually happened:
It didn't

Steps to reproduce:
1. type "/execute @p ~ ~ ~ /tp "
2. try to tab complete.
3. Notice that nothing happens.

First screenshot: before pressing tab.
Second Screenshot: after pressing tab.