Semi-protect admin boundaries by default

[RicoZ]

make it harder to move nodes of administrative boundaries by accident or otherwise damage them. Administrative boundaries do not change very often but are very frequently tied to waterways making them highly susceptible to accidental change.

It may be already possible to achieve a lot with filters - but a one-click solution or rather default-on-protection setting would be preferable for many users.

Also, in cases when admin boundaries and other ways are overlapping it can be very tricky to edit anything without modifying the boundary and filters don't seem to help there.

Related to #4236

[RicoZ]

as an UI idea, the dialog "you are trying to move an object with more than 20 nodes" proved valuable to me. So a similar one when an operation affects an admin boundary in any way would help a lot. With options to disable or perhaps finetune future warnings etc.

[anonymous]

it depends how the admin boundary is defined, if it IS the waterway, then it is logical that refining the waterway will also automatically (and correctly) refine the boundary.

[skyper]

Replying to anonymous:

it depends how the admin boundary is defined, if it IS the waterway, then it is logical that refining the waterway will also automatically (and correctly) refine the boundary.

But overlapping ways are always an error. Either they are defined as the waterway and the waterway should be a member of the boundary relation or they are defined seperately and should have their own ways which should not overlap. As JOSM allows to edit within millimetres it should not be a problem to have two ways right next to each other which will never be seen on any rendered map.

EDT: The major problem I have is that especially community borders are often mapped wrong (overlapping) and/or the sources are not good enough.

[RicoZ]

Replying to anonymous:

it depends how the admin boundary is defined, if it IS the waterway, then it is logical that refining the waterway will also automatically (and correctly) refine the boundary.

But you do not want to put a state border into a culvert for example.

If refining the waterway would result in improved accuracy of the admin boundary than the original data was obviously not worth protecting - but in central Europe we have very high quality freely available data for many admin boundaries and improving those is not possible.

[lists@…]

Something like a warning of the type "you are trying to make changes to an administrative border, are you sure this is correct?" with a YES/NO/CANCEL type choice would probably do, than mappers are warned, choosing NO or CANCEL will prevent the change, while a YES means the mapper is aware that he tries to change a border, and that it is a valid change. That way it will be semi-protected and avoiding accidental edits.

[Don-vip]

Administrative boundaries can change more often in some countries than others. In France for example in the past 10 years we had a lot of changes at communal and regional level. This change would upset a lot of people.