Fixes #932 - path issues with Git 2.25 on Windows

https://github.com/git-for-windows/git/issues/2478

src/git/git.ts

@@ -1018,7 +1018,8 @@ export namespace Git {
 
 	export async function rev_parse__show_toplevel(cwd: string): Promise<string | undefined> {
 		const data = await git<string>({ cwd: cwd, errors: GitErrorHandling.Ignore }, 'rev-parse', '--show-toplevel');
-		return data.length === 0 ? undefined : data.trim();
+		// Make sure to normalize: https://github.com/git-for-windows/git/issues/2478
+		return data.length === 0 ? undefined : Strings.normalizePath(data.trim());
 	}
 
 	export function shortlog(repoPath: string) {

src/system/string.ts

@@ -1,5 +1,6 @@
 'use strict';
 import { createHash, HexBase64Latin1Encoding } from 'crypto';
+import { isWindows } from '../git/shell';
 
 const emptyStr = '';
 
@@ -58,6 +59,7 @@ export namespace Strings {
 		return secs * 1000 + Math.floor(nanosecs / 1000000);
 	}
 
+	const driveLetterNormalizeRegex = /(?<=^\/?)([A-Z])(?=:\/)/;
 	const pathNormalizeRegex = /\\/g;
 	const pathStripTrailingSlashRegex = /\/$/g;
 	const tokenRegex = /\$\{(\W*)?([^|]*?)(?:\|(\d+)(-|\?)?)?(\W*)?\}/g;
@@ -149,6 +151,11 @@ export namespace Strings {
 			normalized = `/${normalized}`;
 		}
 
+		if (isWindows) {
+			// Ensure that drive casing is normalized (lower case)
+			normalized = normalized.replace(driveLetterNormalizeRegex, (drive: string) => drive.toLowerCase());
+		}
+
 		return normalized;
 	}