/tp, /testforblock and /dumpblocknames are not showing outputs

Verification builds: 466466 (1.2)

Summary:
The /tp, /testforblock and /dumpblocknames are not working as intended.

Impact:
Difficulty working on mash-up pack as it's difficult to obtain coords of blocks.

Repro Steps:
1. Try running `/tp ~ ~ ~`, no coords are output.
2. Try running `/dumpblocknames (coords)`, nothing gets output
3. Try running `/testforblock ~ ~-1 ~ redstone_block 0` whilst standing on a redstone block, the game only outputs coords if failed, if successful nothing is output.

Observed Results:
Coords are not reported in the chat.

Expected Results:
Coords should be displayed in the chat.

*Screenshots/Videos attached: * No