OK I understand better now.

No -spacemode option at all is fully backwards compatible with 8.6. That is, neither none, nor trim nor exact gives the same display as in 8.6 in all cases.

This is because of your opinion that bug reports [1082213fff] and [1754051fff] are invalid. These bugs were fixed in 8.6 (legacy code), but you have reverted the behavior in the revised_text version.

Okay, let's keep things as they are. but I'll add a note in #466] so that I (at least) can remember this next time it puzzles me.