Fixes issues showing uncommitted and staged content

src/commands/diffWith.ts

@@ -113,8 +113,8 @@ export class DiffWithCommand extends ActiveEditorCommand {
             }
 
             const [lhs, rhs] = await Promise.all([
-                Container.git.getVersionedFile(args.repoPath, args.lhs.uri.fsPath, args.lhs.sha),
-                Container.git.getVersionedFile(args.repoPath, args.rhs.uri.fsPath, args.rhs.sha)
+                Container.git.getVersionedUri(args.repoPath, args.lhs.uri.fsPath, args.lhs.sha),
+                Container.git.getVersionedUri(args.repoPath, args.rhs.uri.fsPath, args.rhs.sha)
             ]);
 
             let rhsSuffix = GitService.shortenSha(rhsSha, { uncommitted: 'working tree' }) || '';

src/git/gitService.ts

@@ -1677,7 +1677,7 @@ export class GitService implements Disposable {
         return GitTreeParser.parse(data) || [];
     }
 
-    async getVersionedFile(
+    async getVersionedUri(
         repoPath: string | undefined,
         fileName: string,
         ref: string | undefined
@@ -1692,6 +1692,16 @@ export class GitService implements Disposable {
             return undefined;
         }
 
+        if (Git.isStagedUncommitted(ref)) {
+            const path = paths.resolve(repoPath || '', fileName);
+            return Uri.parse(
+                `git:${path}?${JSON.stringify({
+                    path: path,
+                    ref: '~'
+                })}`
+            );
+        }
+
         return GitUri.toRevisionUri(ref, fileName, repoPath!);
     }