Also charcoal apparently doesn't work as fuel anymore. (Creating a fuel item tag might be a good idea?)
I got a bit confused that MC-32296 got marked as a duplicate of this one.
After reading the comments I understood, that they are just different manifestations of the same issue.
Still I would like to suggest changing the description of this issue to contain a short notice about 1-tick unpowering of repeaters being affected too.
@Fabian Röling:
Maybe I didn't manage to say what I was trying to say. So let me take it in chronological order:
Minecraft 1.0 (1.0.0-RC1): The single redstone dust texture changed from a + to a dot. From this on it doesn't look like it is connected to all 4 adjacent blocks anymore but it still powers them.
Minecraft 1.3.1 (12w25a) until Minecraft 1.8: Redstone can now be placed on upside down halfslabs. It is possible to create what we see in the 1.8 picture. While it is irritating, it is still consistent with other behaviour, because we know, that the dot represents a connection to all 4 sides (while not showing them).
Since Minecraft 14w46a: The redstone now connects to the redstone on the slab, but still not to the pistons making it super counterintuitive why it powers them. It really should have stayed a "+" in the first place.
Also notice, how the behaviour never changed. It's just a problem of how to show it.
I hope that clarifies what I tried to say in my last post.
Yours sincerely, Shildifreak
(About the other mentioned issue of the redstone not going up the side of nonsolid blocks: In my opinion thats already how it's supposed to be, because it corresponds to the signal going up the block, but not down. If one would now add the redstone texture on the side of an upside down stair/observer/glowstone/etc. that would make things even more mixed up and irritating.)
In the older "redstone redirection - 1.8 behaviour.png" picture we can see, that the redstone used to be a dot. And the dot once was a cross.
So like a single dot powering all 4 horizontal adjacent blocks, this behaviour was once consistent with the texture and should therefore be called intended.
So I suggest fixing the issue by remerging it with the dot visualisation, and then getting rid off those inconsistencies together, by displaying connections to all adjacent blocks.
PS.: Consistency helps a lot learning redstone. So I think this bug is not as unimportant as it might seem.
affects 18w16a