The bug
When the Render Distance setting is changed, the "view distance" that appears in the log is 2 chunks lower than the chosen setting.
For example, when changing the render distance from 10 to 9, this appears in the log: Changing view distance to 7, from 8.
This may be why the distance fog is not working correctly in 1.14.
Comments


Confirmed not completely fixed in 1.15-pre1.

It's a question of definitions. The "render distance" sets how many chunks the game loads. The edge chunks are never rendered.

This appears to be the same or similar issue as MC-159361. And while the value that appears in the log may have been fixed, the effect seen ingame is not.
If the edge chunks are never rendered, why would they be part of render distance? Also they sometimes appear to be rendered - for example when switching from higher render distance to lower value. Client chunk cache value after changing from lower to higher render distance value seems to confirm that - the value is lower than what render distance would imply. For example when changing from render distance 2 to 8 (after ensuring that the entire surrounding area is fully generated), the expected amount of chunks would be 289, but it is 225 instead (corresponding to render distance 7)
Even if it's just a question of definition, at least the visual fog no longer seems to match what chunks are actually loaded, causing ugly edges at the edge of the render distance.

It seems to me that problem still exists in 21w08b
Marked as fixed in 1.15 pre-1, but I disagree. When changing the render distance, it's now off by 1.
When changing the render distance to 16 (from 17), the log says: "Changing view distance to 15, from 16".