fix a number of regressions in the flight waypoint list by changing t…

[zhexu14]

…he indexing and finding a work-around to blocking of signals

This PR addresses some (but not all) recently reported issues with the waypoints screen reported in Issue #3188 . This PR was tested by:

• Changing the waypoint altitude and confirming it shows up correctly when reloading the waypoint list window and on the map
• Adding a waypoint and confirming that it shows up immediately and persists on reload
• Deleting a waypoint (except the first waypoint) and confirming that it is removed immediately and persists on reload,

Known issues: first waypoint (typically hold) cannot be deleted -- still looking into this one.

[codecov]

Codecov Report

Merging #3191 (0027dbe) into develop (990f1c3) will not change coverage.
The diff coverage is n/a.

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  Coverage    45.75%   45.75%           
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  Files          474      474           
  Lines        25819    25819           
  Branches      4521     4521           
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  Hits         11813    11813           
  Misses       13985    13985           
  Partials        21       21           

[Starfire13]

My recollection was that deleting the non-nav waypoints would screw up fast forward interruption, so might want to check if that is still triggering fine. It might already have been fixed as I haven't deleted those in a while.

[DanAlbert]

My recollection was that deleting the non-nav waypoints would screw up fast forward interruption, so might want to check if that is still triggering fine. It might already have been fixed as I haven't deleted those in a while.

That's not a bug. If you alter your flight plan it stops being whatever specific flight plan (DEAD , BARCAP, CAS, etc) and becomes just "custom" because it not longer meets the requirements of the other flight plan. We can't reason about custom flight plans.

[Starfire13]

I realise that. My point is that it might not be worthwhile to look into implementing a way to delete the first waypoint if it does still break fast forward and we have to tell users not to do it anyway.

[DanAlbert]

Not everyone uses fast forward.

For what it's worth, I agree, I don't think these things should be editable at all if it's going to break stuff, but that's been true forever and will be until #270 is done, and people complain if it breaks (that's what caused this PR, after all).

[zhexu14]

My recollection was that deleting the non-nav waypoints would screw up fast forward interruption, so might want to check if that is still triggering fine. It might already have been fixed as I haven't deleted those in a while.

I did some testing on this one and it seems that deleting both nav and non-nav waypoints will break fast-forward. The exception being raised though is in a different part of the code, so would probably be better captured in a different PR if we think it's worthwhile fixing.