Multi-storey, multiple roof bug - Gap caused by scaffolding

Summary: This is a hard one to explain… I built an L-shaped building with a second floor. The second floor was a rectangle along the long part of the L. I placed a 4-sloped roof on the upper floor. I then decided on a 2-sloped roof for the remaining bit of the first floor. When I placed this, the upper roof changed to a 2-sloped roof. I selected the upper roof once more and made it 4-sloped. A one block gap appeared along the inner edge of the upper roof. It was above the wall. The overhanging bit of roof remained where it was supposed to be. Pressing the N/S/E/W toggle buttons on the roof editor moved the gap to another edge of the roof.

Steps to reproduce:

This might be difficult to reproduce - I wasn’t paying attention at the time…
See pictures below if my instructions are poor!

  1. Build L-shaped building.
  2. Add walls
  3. Add second floor to long part of L (leaving the jutting bit uncovered)
  4. Add walls to second floor
  5. Add N/E/S/W wall to top floor
  6. Add N/S or E/W wall to bottom floor, such that the gable is on the tip of the building.
  7. (Upper roof will change to match the bottom roof)
  8. Click upper roof and reselect N/E/S/W for its configuration

If the gap is present, playing with the N/E/S/W controls will move it to other edges.

Expected results: Both roofs are placed independently, altering one doesn’t change the other, no gaps are created.

Actual results:

My building, design phase, as of Step 8 above

After clicking/reclicking all of the cardinal buttons, the gap switched sides.

Scaffolding was placed where the gap is - No idea why this was placed…

Near completion… scaffolding was being taken down.

Placed a ladder to remove the roof scaffolding. It was not removed, despite access to the second floor. Roof access was required.

It was successfully removed, but nothing was placed in its stead.

Version: r2395 x64