Fixes diff w/ working on virtual repos

Refs: #2300

src/env/node/git/localGitProvider.ts

@@ -694,8 +694,9 @@ export class LocalGitProvider implements GitProvider, Disposable {
 		}
 
 		// Short-circuit if the path is relative
-		if (typeof pathOrUri === 'string' && !isAbsolute(pathOrUri)) {
-			return Uri.joinPath(base, normalizePath(pathOrUri));
+		if (typeof pathOrUri === 'string') {
+			const normalized = normalizePath(pathOrUri);
+			if (!isAbsolute(normalized)) return Uri.joinPath(base, normalized);
 		}
 
 		const relativePath = this.getRelativePath(pathOrUri, base);

src/git/gitProviderService.ts

@@ -856,8 +856,9 @@ export class GitProviderService implements Disposable {
 		}
 
 		// Short-circuit if the base is already a Uri and the path is relative
-		if (typeof base !== 'string' && typeof pathOrUri === 'string' && !isAbsolute(pathOrUri)) {
-			return Uri.joinPath(base, normalizePath(pathOrUri));
+		if (typeof base !== 'string' && typeof pathOrUri === 'string') {
+			const normalized = normalizePath(pathOrUri);
+			if (!isAbsolute(normalized)) return Uri.joinPath(base, normalized);
 		}
 
 		const { provider } = this.getProvider(base);

src/plus/github/githubGitProvider.ts

@@ -281,8 +281,9 @@ export class GitHubGitProvider implements GitProvider, Disposable {
 			}
 		}
 
-		if (typeof pathOrUri === 'string' && !maybeUri(pathOrUri) && !isAbsolute(pathOrUri)) {
-			return Uri.joinPath(base, normalizePath(pathOrUri));
+		if (typeof pathOrUri === 'string' && !maybeUri(pathOrUri)) {
+			const normalized = normalizePath(pathOrUri);
+			if (!isAbsolute(normalized)) return Uri.joinPath(base, normalized);
 		}
 
 		const relativePath = this.getRelativePath(pathOrUri, base);