Comment 5 for bug 260359

Yes I accidentally discovered this function (convert a line to a guide) while making the attached image. It is very helpful for some cases, but if you want to draw something like the example in my image it's not so useful I think.

In my imaginary feature, the node would snap so that the line(s) connected to it would align with the guide closest to it/them in angle (not spatially). Just like Ctrl+pen tool for instance, which snaps to angles in 15 degree intervals. If you have several guides, it would simply choose the one with an angle closest to the angle you're pointing at. I can see however how that may be a problem when editing a node in a path, where two lines are affected by the movement of one path... I guess it would have to have a tolerance for alignment in that case.

Your idea about keeping the angle with Ctrl is very good, but it's not quite what I'm after since it will only help if the line is already at the correct angle.