CONTOUR is KO on OSX on x86 since circa one year

[alaingdl]

Since ~ March 2023, on two Mac with processor x86, CONTOUR is not OK : no contour lines plotted on contour, findgen(12,12)

I go back till Version 1.0.2 Git and same problem.

(I cannot compile nowadays the current 1.1 version on those Mac due to troubles related to Xcode 😞 :)

This problem with CONTOUR don't exist on Mac running on proc. M2

Concerning the testability of that king of problems, I suspect we can count the number of black & with pixels (we had such discussion with @GillesDuvert long time ago)

[GillesDuvert]

@alaingdl I've no x86 OSX at my disposal to test this. You're on your own 😦

[alaingdl]

A colleague reported now that (on his OSX x86_64) this bug is still present today with a version of GDL compiled a month ago ...
I will try to clarify the context but I have no access to the machine now (and I have to check too on OSX with M2 ...)

[alaingdl]

Side effect : in CONTOUR, keywords PATH_XY= and PATH_INFO= do nothing silently ! I think it would be better to emit a warning instead !

[alaingdl]

I confirm I can reproduce the problem on OSX M2. Basic contour is OK. But :

contour, dist(50), nlevels=1
contour, dist(50), level=findgen(100)

plot nothing on OSX.

It is fine on my Linux

Since plplot was moved into GDL by Gilles, I think it is for him ! @GillesDuvert