#549 2.0.8 Freeze when drawing rectangle on complex drawing

[poikilos]

The problem is difficult to reproduce since it happened while drawing a rectangle. The included 4 files are all produced by working with one file. The diagram is a watch, drawn from two views. different types of parts are on different layers. Someone I was helping made this. I told them that the side view should include rectangles to show where the gears should be placed on the z axis. When he was adding the rectangles, the program crashed, and now opening the file crashes the program (this does not occur with the file proceded by a number sign).
He was originally using 2.0.6. I upgraded him to 2.0.8, but opening file still freezes the program.

[Dongxu Li]

Could you try the latest nightly builds, or build from source (2.0 branch)?

We fixed quite many bugs after 2.0.8, and it's important to resolve serious bugs like this one before releasing 2.0.9.

https://sourceforge.net/projects/librecad/files/Windows/

[poikilos]

The same behavior occurs in Nightly 2.0.8-106-g513e499 (latest file freezes the program, but the backup file preceded by pound sign does not)

[Dongxu Li]

I added a first-aid to the 2.0 branch:

https://github.com/LibreCAD/LibreCAD/commit/be5d23c307b02e35ab6b4b4264d34bcca8dfbf38

This patch only fixes potential infinite loop, but we need to figure out whether the dxf was generated/read properly.

Rallaz can review the actual dxf file problem underneath.