Originally created by: BilgeGates
Originally owned by: BilgeGates
What happened?
In exportRaster.ts, canvas.toBlob() is asynchronous. If the export is cancelled between canvas creation and the callback firing, the finally block resets canvas.width/height to 0 while toBlob may still be reading pixel data — potentially producing a corrupted or empty blob.
File: src/shared/utils/exportRaster.ts
Steps to reproduce
- Start a high-resolution export (e.g. 8× quality)
- Click Cancel immediately after starting
- Observe the exported file if the download still triggers — may be corrupted or empty
Expected
Cancelling an export produces no output. The canvas is only reset after toBlob has fully resolved.
Actual
Canvas dimensions are reset while toBlob may still be executing, risking a torn blob.
Root cause
The exportState.cancelled check inside the toBlob callback fires after the canvas is already reset. Canvas reset should only happen after the toBlob callback has fully resolved.
Browser & OS
Safari on iOS and macOS — most sensitive to canvas memory pressure and race conditions.
Before submitting
- [x] I searched existing issues and this is not a duplicate.
