From 6ce1ff5c6fb29784cf0fd99b84fa9e2cbe2b3944 Mon Sep 17 00:00:00 2001
From: GDR User <gdr.user@example.com>
Date: Sun, 22 Feb 2026 21:02:30 -0600
Subject: [PATCH] Fix percent-encoded drive letter colon (%3A) in Windows file
 URIs

Some LSP clients send file URIs with the drive letter colon percent-encoded
as %3A (e.g., file:///c%3A/Users/...). The existing _dosPathRegex only
matches literal colons, causing getFilePath() to fail to strip the leading
slash and decode the path correctly on Windows.

- Update _dosPathRegex to also match %3A/%3a after the drive letter
- Decode percent-encoded colon back to ':' after stripping the leading slash
---
 packages/pyright-internal/src/common/uri/uri.ts | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/packages/pyright-internal/src/common/uri/uri.ts b/packages/pyright-internal/src/common/uri/uri.ts
index 6efbf2be0671..19801f444bf2 100644
--- a/packages/pyright-internal/src/common/uri/uri.ts
+++ b/packages/pyright-internal/src/common/uri/uri.ts
@@ -31,7 +31,7 @@ export type SerializedType = [UriKinds, ...any[]];
 import type { Uri as UriInterface } from './uriInterface';
 export interface Uri extends UriInterface {}
 
-const _dosPathRegex = /^\/[a-zA-Z]:\//;
+const _dosPathRegex = /^\/[a-zA-Z](?::|%3[aA])\//;
 const _win32NormalizationRegex = /\//g;
 
 // Returns just the fsPath path portion of a vscode URI.
@@ -49,9 +49,11 @@ function getFilePath(uri: URI): string {
     }
 
     // If this is a DOS-style path with a drive letter, remove
-    // the leading slash.
+    // the leading slash and decode percent-encoded colons.
     if (filePath.match(_dosPathRegex)) {
         filePath = filePath.slice(1);
+        // Decode %3A/%3a back to ':' for Windows drive letters
+        filePath = filePath.replace(/^([a-zA-Z])%3[aA]/, '$1:');
     }
 
     // vscode.URI normalizes the path to use the correct path separators.