Maximum stack size exceeded when brushing large areas very fast

[philippotto]

Context

Volume Annotation.

Current Behavior

Crashes with maximum call stack size exceeded error.

Also see #6055 (comment)

Steps to Reproduce the bug

• Cannot reproduce the bug anymore / needs deeper investigation.

Unfortunately, the repro is not 100% reliable:

1. Open new volume annotation
2. Brush large areas very fast and click save in between

Your Environment for bug

• Browser name and version: e.g. Chrome 39
• Operating System and version: e.g. Windows 10
• Version of WebKnossos (Release or Commit):
• Specific to long-running jobs (set jobsEnabled=true in application.conf)
• Specific to webKnossos.org (set isDemoInstance=true in application.conf)

[daniel-wer]

Just adding my repro steps. For me it was enough to select the largest brush size, zoom out a fair bit and then do three to four fast and large brush strokes across the whole viewports.