Fix #5428: DataGrid with template columns causes crash when scrolling #11068
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Pull Request Overview
This PR fixes a null reference exception crash that occurs when scrolling DataGrid controls with template columns. The issue manifests as occasional application crashes that cannot be handled by user code during items-control scrolling operations.
- Adds a null check for dataItem before attempting to access it in the automation peer collection logic
- Skips processing of null items instead of crashing when they are encountered
- Provides a defensive programming approach to prevent unhandleable exceptions
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Fixes #5428
Main PR
Description
During scroll of items-controls there are occasional null reference exceptions that crash the application. There is no chance to handle these exceptions, because there is no user code in the stack trace.
This PR adds the missing null check to avoid the null reference exceptions.
Customer Impact
Actually there are occasional crashes of the application that are not fixable by user code, see e.g. dotnet/ResXResourceManager#430
This problem occurs in any version of DotNet or NetFramework.
This PR fixes the application crashes.
Testing
No testing, impossible to build and run locally.
Risk
Low, it's just adding a null-check before code that crashes on null items.
Microsoft Reviewers: Open in CodeFlow