Describe the issue

We support a keyboard shortcut to re-indent python
We use the indentRange command for the whole document
We support both 4 space and 2 space indentation

So it's quite common for a user to have 4 space indentation and then re-indent to 2 spaces.

This works well, but we've found some edge cases where it seems broken
See reproduction example
The edge cases we've found involve try/except
But there may be some related ones.

Browser and platform

NA

Reproduction link

https://codemirror.net/try/#c=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