Strange Ctrl-Z behavior in DWC editor

[zapta]

To reproduce (using Chrome/Windows):

1. Open config.g for editing in DWC
2. Hit ctl-z and observe the text

Expected: No change (undo history should be empty)
Actual: Entire file text is deleted.

If the file was edited and saved a few times, clicking ctl-z multiple times is even more strange, as if undo history was retained from previous editings.

[Phaedrux]

This is in 3.4 I assume? Browser?