fix(ios): prevent crash when VTCreateCGImageFromCVPixelBuffer fails (#1545)

[prachiFam]

Line 147-165: VTCreateCGImageFromCVPixelBuffer now checks status before using
✅ Line 185-188: jpegData() safely handled (can return nil)
✅ Line 218-226: Reset flag in catch block + proper error propagation
✅ Line 277-296: Array bounds validated before access
✅ Line 44-45 & 428-437 & 756-770: Observer tracking prevents double-add/remove crashes

Description

Fixes EXC_BREAKPOINT crash in iOS when VTCreateCGImageFromCVPixelBuffer fails.

Problem

The current code force-unwraps the CGImage after calling VTCreateCGImageFromCVPixelBuffer without checking if the operation succeeded. When the camera is interrupted (phone call, app switching, etc.), this causes an EXC_BREAKPOINT crash.

Solution

• Check the return status of VTCreateCGImageFromCVPixelBuffer
• Safely unwrap the CGImage using guard let
• Reset imagesCurrentlyBeingProcessed flag on error to prevent scanner from getting stuck
• Use captured buffer reference instead of self.latestBuffer to avoid race conditions

Testing

Tested on iOS 17.x with:

• Normal barcode scanning
• Camera interruption (phone call)
• App switching during scan
• Device sleep during scan
• No crashes observed

Related Issues

Fixes #1545 [iOS] EXC_BREAKPOINT crash in captureOutput when VTCreateCGImageFromCVPixelBuffer fails

Checklist

• I have tested my changes
• I have updated documentation (if needed)
• I have added tests (if applicable)

[navaronbracke]

I still need to give this a proper review, but does this also fix #883 and #1543 ?

If so, can you update the PR description?

[navaronbracke]

@juliansteenbakker from a quick look, the general idea looks fine, but it sounds like the PR has some AI-coded boilerplate. I'll probably redo the relevant checks in a new PR.

[jvk75]

Any change to get this merged and published? I started to see crashes due the force unwrapping in the cgImage :(

[navaronbracke]

I am planning to get this out tomorrow, but I'm a bit tight on other schedules at the moment.

[navaronbracke]

edit: currently looking into this now, will publish an update later today