Conversation
This was referenced Sep 21, 2026
timfroh
marked this pull request as ready for review
September 21, 2026 21:57
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Description
The Pad Properties dialog has a small canvas showing a preview of the pad. Its display settings were created in a local variable during setup, but the canvas kept a reference to them after that variable was destroyed.
A graphics error in WASM triggered a rebuild of the preview renderer, which then accessed those expired settings. This broke observer registration: when a renderer was cleaned up,
remove_observercould no longer find its registration and asserted.The fix keeps the settings alive for the lifetime of the preview and destroys the canvas before releasing them.
Motivation
Double-clicking a pad could trigger the assertion. Closing Pad Properties with OK or Cancel could also leave selection unresponsive—both clicking items and dragging a selection rectangle stopped working. Both symptoms are confirmed fixed with a compiled WASM binary.
There will be a separate fix in PCBJam for the underlying graphics error that triggered renderer recovery. This PR fixes the KiCad lifetime bug that made that recovery unsafe.