Redstone with strength 1 behaves inconsistently

When redstone with strength 1 connects upwards and to the side, the block with the unpowered redstone on top will not be powered even though the powered redstone dust points into it.

Top left section and bottom right section show the dust behaving as expected with strength>1 or when not connecting sideways.

 

The top right shows a direct corner with strength 1 not powering the "connected" block (marked with the red circle).

The bottom right shows the case where the connection forces a redstone "dot" into a line. This does also not power the "connected" block (marked with the red circle), but does power the "unconnected" block as it should.

 

This looks to be an oversight handling the special case of redstone with strength 1 moving upwards after either a corner or a redstone dot that was forced into a straight line.
It has been like that for a long time, but I especially find the bottom left case counter-intuitive.
The other cases can be justified by behaving "like the unpowered dust is not there", but if that is the intended behavior the bottom left case should "work" as well.