When standing in/under a door, torch, trap door, stairs, slab, ladder, vine, gate, wooden fence, two block tall vegetation, iron bar, glass pane, cobweb or sign with a block directly above it, the player and items you are holding turn dark (zero lighting).
Only happens if the block above is solid. Transparent and non solid blocks, (glass, slabs, stairs, chest....) have normal lighting.
In Build 14, this has been fixed, but only for stone fencing and paintings.
This bug also occurs if the door is replaced with any of a trap door, fence, gate, glass panes, iron bars, vines, ladder, two block tall vegetation, sign, spiderweb or a torch that is placed directly beneath the block that is above the player's head.
Samsung Galaxy S4 (phone) Android 5.0.1 MCPE 0.11.0 build 10 (tested both creative and survival)