Allow signed distance for ST_Project

[komzpa]

ST_Project now falls with

ERROR: XX000: Distance must be between 0 and 2.00151e+07

when passed distance is negative.

for cases when you have just speed, time delta and heading and would like to calculate position along the path line that corresponds to this point, it breaks on negative time deltas.

This can be implemented as adding 180 degrees to the angle and taking abs(distance).

[robe]

Darafei,

If you can provide a patch for this within next week I'll accept. Otherwise going to have to punt till 2.5.

[komzpa]

​https://github.com/postgis/postgis/pull/138

tests are green, and it bothers me: the middle commit added a test but not expected output for it, and it's green too.

[robe]

not following which test you are talking about also looks like you are missing a doc update. I can add the doc update on that so don't worry about it.

[robe]

In 15598:

Allow signed distance for ST_Project (Darafei Praliaskouski)
Closes ​https://github.com/postgis/postgis/pull/138
Closes #3709