As of r11396, the lesstif HID should work on every system, with both lesstif and motif.

The long standing bug was a rather tricky one to figure. I never experienced it on my main systems but only one box while other users/developers consistently reported it. I thought it was a motif version problem, maybe something changed recently and others use a too new or too old version compared to my system.

Then I started to work on the attribute dialog upgrade and for some of the lesstif code I decided to set up a smallish test bench in work/ to try out ideas without having to compile and run pcb-rnd. And the minimal "hello world" test program immediately produced the same runtime error. I went on and copied the official test programs from motif and lesstif, and boom, the same error!

That's when I started to investigate the build parameters. It turned out the order of linking must be -lXm _before_ -lXt. If the order is wrong, there is no link time error, but the misleading runtime error.

And the difference between my systems and everyone else's? Opengl. I don't have it, so my link list had lesstif libs before gtk libs and within the lesstif lib link set the order is -lXm -lXt. With opengl, -lXt got on the list with opengl libs, way before lesstif, that's how we ended up with "-lXt <a_lot_of_other_stuff> -lXm -lXt", from which the second -lXt got removed as redundant.

Solution: this is a very special case. I've been coding C on various UNIX systems since about 1999, and never seen a link order causing such runtime error. Nevertheless, we may later on have other link order problems which would cause linking error, so I decided to go for a generic/proper solution. I've added a new feature in scconfig so that two items in a list can be reordered to meet a specific requirement. It does that by minimal change to the list, e.g. moving the out-of-order item only, right before (or after) the target word. The two lines that got added to src/Makefile.in:

# Lesstif requires that -lXm is before -lXt or else there is a runtime BadWindow
order /local/pcb/LDFLAGS {-lXm} {before} {-lXt}

This moves -lXm to right before -lXt if both are present on LDFLAGS and are in the wrong order.