Additional try/catch handling in DocumentsSyncService #392
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Summary
This PR adds error handling via try-catch blocks to three methods in the document synchronization service: OnBeforeDocumentWindowShow, Subscribe, and UnsubscribeOnClosed. It also fixes indentation in OnAfterAttributeChangeEx.
Critical Issues
The primary concern is state inconsistency caused by swallowing exceptions. When exceptions occur partway through operations, state tracking collections (isSubscribed, openNotificationSend) may indicate successful subscription while actual event handlers were never attached or only partially attached. This creates a disconnect between the service's internal state and reality, preventing retry attempts and potentially causing memory leaks.
Considerations
- Consider whether returning
VSConstants.S_OKafter catching exceptions inOnBeforeDocumentWindowShowis appropriate, as it signals success to Visual Studio even when the operation failed. - These event handler subscription patterns might benefit from an all-or-nothing approach where either all subscriptions succeed or all are rolled back on failure.
…ouldn't be executed.
tomaszgolebiowski
approved these changes
Nov 26, 2025
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Adds defensive try-catch blocks with error logging to three VS event handler methods in DocumentsSyncService to prevent unhandled exceptions from destabilizing Visual Studio.
VS extensibility callbacks must not throw exceptions. Unhandled exceptions in IVsRunningDocTableEvents can crash Visual Studio or disable the extension.
Test plan
N/A