IDE freeze when pasting code in Grails / GSP: some block intersects with whitespace / child block start is less than parent block start

```
2025-05-15 16:23:52,474 [ 466571] SEVERE - #c.i.f.RangesAssert - child block start is less than parent block start in #GSP #formatter
Range: [0,12934], text fragment: [0,12934]
2025-05-15 16:23:52,482 [ 466579] SEVERE - #c.i.f.RangesAssert - some block intersects with whitespace in #GSP #formatter
Range: [12938,0], text fragment: [0,12938]
```
IU-251.25410.129, JRE 21.0.6+9-b895.109x64 JetBrains s.r.o., OS Windows 11(amd64) v10.0 , screens 2560x1080 (100%), 1920x1080 (100%)
Auto-uploaded logs URL (accessible to JetBrains employees only):

When attempting to paste a code block the editor locks up and I need to use Windows Task Manager to kill IntelliJ. I'm going to try to attach a video showing this. It happens every time, even after multiple reboots.

---

*Imported from [IDEA-372811](https://youtrack.jetbrains.com/issue/IDEA-372811) · Type: Performance Problem · Votes: 0*
*Comments, attachments, dates and reporter are not part of the export — follow the link above for the full history.*

Reproduce the freeze by pasting a code block in a Grails/GSP editor using the reported IntelliJ IDEA and Windows setup. Start with the GSP formatter errors in the issue, especially the invalid range and whitespace intersection; done means pasting no longer locks the editor and the reported range errors are resolved.

Written by the indexing model from the issue text.