Fix canonical URI cache invalidation on path casing changes

[zainnadeem786]

Fixes #328677

Summary

Fix canonical URI cache invalidation when a filesystem provider's path-casing capability changes.

Root Cause

UriIdentityService recomputes the new per-scheme ignorePathCasing value after a filesystem provider registration or capability-change event, but the existing implementation compares the newly computed value to itself.

Because this condition is always true, the listener returns before clearing cached canonical URI entries for the affected scheme.

As a result, direct URI comparisons can reflect the updated path-casing behavior while asCanonicalUri() continues returning URI values cached under the previous casing semantics.

Change

Compare the previously cached path-casing value with the newly computed value:

- if (newIgnorePathCasingValue === newIgnorePathCasingValue) {
+ if (oldIgnorePathCasingValue === newIgnorePathCasingValue) {

This allows the existing canonical URI cache invalidation logic to run only when the provider's path-casing behavior has actually changed.

Regression Test

Added a focused URI Identity regression test that:

• caches foo://bar/BANG while the provider scheme is case-insensitive;
• confirms foo://bar/BANG and foo://bar/bang initially resolve to the same canonical URI;
• changes the provider capability to PathCaseSensitive;
• emits the provider capability-change event;
• verifies direct URI comparison reflects the new case-sensitive behavior; and
• verifies asCanonicalUri(foo://bar/bang) no longer returns the stale uppercase URI.

The test fails on the previous implementation and passes after the fix.

Validation

• npm run compile

• .\scripts\test.bat --grep "asCanonicalUri clears cache when provider path casing changes"

  • 1 passing

• .\scripts\test.bat --grep "URI Identity"

  • 8 passing

[Copilot]

Pull request overview

Fixes stale canonical URI caching when filesystem path-casing capabilities change.

Changes:

• Corrects old-versus-new casing comparison.
• Adds a focused regression test for cache invalidation.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
src/vs/platform/uriIdentity/common/uriIdentityService.ts	Corrects cache invalidation condition.
src/vs/platform/uriIdentity/test/common/uriIdentityService.test.ts	Tests runtime casing-capability changes.