Most of the light emiting blocks that takes up a full block are too permissive with sunlight.

Steps to reproduce :

• create a completely dark room with a redstone lamp on the ceiling (for exemple) and put a solid block above it (see picture 1)

• power the redstone lamp (see picture 2)

• get inside the room (and cover the hole in the ceiling : it was just here to show you the redstone lamp) and observe the light level (see picture 3)

Here is our first problem : with this solid block on top of the redstone lamp, there is no way skylight can pass at all, but as you can see :
"Light 11 (7 sky,11 block)"

• now, break the redstone lamp and the observe the light level : (see picture 4)
  this time, it's correct : "Light 0 (0 sky,0 block)"

• replace the redstone lamp and observe the light level agin : (see picture 5)
  "Light 11 (0 sky,11 block)"
  The exact same configuration results in differents light levels, definitly a bug.

Moreover, if you just try to right click repeatedly the redstone block when the light level is "Light 11 (7 sky,11 block)", it may end up updating to "Light 11 (0 sky,11 block)" by itself, which is not the sign of an intended behavior.

Glowstone and Jack-o-lantern work the same, minus the fact that they don't require redstone power. (see picture 6)

(even through these screenshots show : "Biome : The End", i'm in fact in an overworld generated with the custom generation settings recently implemented.)
(I searched for tag "sunlight" to make sure this bug is not a duplicate)