Routing a track from a via to a pad replaces a similar track to a similar pad on the other side of the board

[Johannes Agricola]

I've been having a lot of fun with the push and shove router. However, there seems to be a bug in redundant track detection.

I need to route a track to two pads which are on opposite sides on the board and have the same position and size. Just before the pad, I placed a via, then completed routing to one of the pads (first-track.png). Then I switched back to the other side and completed the track to the other pad. Now I would have expected to have two tracks. However, the first track has been removed (second-track.png).

Repeating the first track then removes the second track, and so on.

Disabling "Remove redundant tracks" allows me to route the second track, so it seems that the second track is detected as a redundant track - while it is definitely not really redundant.

Version info:
Application: kicad
Version: 4.0.1-2.201512121406+6195~38~ubuntu15.04.1-stable release build
wxWidgets: Version 3.0.2 (debug,wchar_t,compiler with C++ ABI 1002,GCC 4.9.2,wx containers,compatible with 2.8)
Platform: Linux 3.19.0-18-generic x86_64, 64 bit, Little endian, wxGTK
Boost version: 1.55.0
         USE_WX_GRAPHICS_CONTEXT=OFF
         USE_WX_OVERLAY=OFF
         KICAD_SCRIPTING=ON
         KICAD_SCRIPTING_MODULES=ON
         KICAD_SCRIPTING_WXPYTHON=ON
         USE_FP_LIB_TABLE=HARD_CODED_ON
         BUILD_GITHUB_PLUGIN=ON

Thank you so much for your great work on KiCAD!

[Johannes Agricola (johannes-agricola)]

Just to make that clear - there is a similar pad on the back side of the board. So here a screenshot, showing B.Cu rendered in front.

[Tomasz Wlostowski (twlostow)]

Hi Johannes,

I'm not sure I fully understand the issue. Which tracks gets removed? Could you make a move showing the issue?

Best,
Tom

[Johannes Agricola (johannes-agricola)]

Hi Tom,

of course. Here I try to route both tracks, alternatingly. Every time I switch between front and back side, you see that the previously routed track is missing: https://vimeo.com/151016368

Cheers,
Johannes

[Chris Pavlina (pavlina-chris)]

Confirmed in 6436.