Fix "Open Referenced File" command for windows paths

extensions/ql-vscode/CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## [UNRELEASED]
 
+- Fix the _CodeQL: Open Referenced File_ command for Windows systems. [#979](https://github.com/github/vscode-codeql/pull/979) 
 - Fix a bug that shows 'Set current database' when hovering over the currently selected database in the databases view. [#976](https://github.com/github/vscode-codeql/pull/976)
 - Fix a bug with importing large databases. Databases over 4GB can now be imported directly from LGTM or from a zip file. This functionality is only available when using CodeQL CLI version 2.6.0 or later. [#971](https://github.com/github/vscode-codeql/pull/971)
 - Replace certain control codes (`U+0000` - `U+001F`) with their corresponding control labels (`U+2400` - `U+241F`)  in the results view. [#963](https://github.com/github/vscode-codeql/pull/963)

extensions/ql-vscode/src/extension.ts

@@ -498,7 +498,7 @@ async function activateWithInstalledDistribution(
   ): Promise<void> {
     if (qs !== undefined) {
       if (await cliServer.cliConstraints.supportsResolveQlref()) {
-        const resolved = await cliServer.resolveQlref(selectedQuery.path);
+        const resolved = await cliServer.resolveQlref(selectedQuery.fsPath);
         const uri = Uri.file(resolved.resolvedPath);
         await window.showTextDocument(uri, { preview: false });
       } else {