fix code diff view

apps/x/packages/core/src/code-mode/git/service.ts

@@ -67,6 +67,17 @@ export async function repoInfo(cwd: string): Promise<GitRepoInfo> {
     return { isGitRepo: true, branch, hasCommits, dirtyCount };
 }
 
+// git status/diff report paths relative to the REPO ROOT, which is not the
+// session cwd when the user opened a subdirectory of a repo as their project.
+// Disk reads must resolve against the root, not cwd.
+async function repoToplevel(cwd: string): Promise<string> {
+    try {
+        return (await git(cwd, ['rev-parse', '--show-toplevel'])).trim() || cwd;
+    } catch {
+        return cwd;
+    }
+}
+
 function stateFromPorcelain(xy: string): GitFileState {
     if (xy === '??') return 'untracked';
     if (xy.includes('R')) return 'renamed';
@@ -75,10 +86,14 @@ function stateFromPorcelain(xy: string): GitFileState {
     return 'modified';
 }
 
-// Working-tree changes vs HEAD with insertion/deletion counts. Untracked files
-// get their line count from disk (capped) since numstat doesn't cover them.
+// Working-tree changes vs HEAD with insertion/deletion counts, scoped to the
+// session directory's subtree (`-- .`): a project opened inside a bigger repo
+// only shows its own changes. Result paths are repo-root-relative (git's
+// porcelain format). Untracked files get their line count from disk (capped)
+// since numstat doesn't cover them.
 export async function status(cwd: string): Promise<GitStatusFile[]> {
-    const out = await git(cwd, ['status', '--porcelain=v1', '-z']);
+    const root = await repoToplevel(cwd);
+    const out = await git(cwd, ['status', '--porcelain=v1', '-z', '--', '.']);
     const entries: Array<{ path: string; state: GitFileState }> = [];
     // -z format: "XY path\0" and for renames "XY newPath\0oldPath\0"
     const parts = out.split('\0');
@@ -94,7 +109,7 @@ export async function status(cwd: string): Promise<GitStatusFile[]> {
 
     const counts = new Map<string, { insertions: number | null; deletions: number | null }>();
     try {
-        const numstat = await git(cwd, ['diff', 'HEAD', '--numstat', '-z']);
+        const numstat = await git(cwd, ['diff', 'HEAD', '--numstat', '-z', '--', '.']);
         // -z numstat rows: "ins\tdel\tpath\0" (renames: "ins\tdel\0old\0new\0")
         const rows = numstat.split('\0');
         for (let i = 0; i < rows.length; i++) {
@@ -126,7 +141,7 @@ export async function status(cwd: string): Promise<GitStatusFile[]> {
             deletions = counted.deletions;
         } else if (entry.state === 'untracked') {
             try {
-                const full = path.join(cwd, entry.path);
+                const full = path.join(root, entry.path);
                 const stat = await fs.stat(full);
                 if (stat.isFile() && stat.size <= MAX_TEXT_BYTES) {
                     const content = await fs.readFile(full, 'utf8');
@@ -154,16 +169,33 @@ export interface FileDiff {
 }
 
 export async function fileDiff(cwd: string, relPath: string): Promise<FileDiff> {
+    // Paths from `status` are repo-root-relative; paths clicked in the chat
+    // timeline are cwd-relative. Resolve whichever interpretation points at a
+    // real file (deleted files fall back to the root interpretation, which is
+    // also what `git show` uses).
+    const root = await repoToplevel(cwd);
+    let gitPath = relPath;
+    let full = path.join(root, relPath);
+    const existsAt = async (p: string) => fs.stat(p).then((s) => s.isFile()).catch(() => false);
+    if (!await existsAt(full)) {
+        const cwdFull = path.join(cwd, relPath);
+        if (await existsAt(cwdFull)) {
+            full = cwdFull;
+            // Realpath both sides — git reports the real toplevel, while the
+            // session cwd may reach it through a symlink (e.g. /tmp on macOS).
+            const realFull = await fs.realpath(cwdFull).catch(() => cwdFull);
+            gitPath = path.relative(root, realFull).split(path.sep).join('/');
+        }
+    }
     let oldText = '';
     try {
-        oldText = await git(cwd, ['show', `HEAD:${relPath}`]);
+        oldText = await git(cwd, ['show', `HEAD:${gitPath}`]);
     } catch {
         // untracked / newly added / no commits — diff against empty
         oldText = '';
     }
     let newText = '';
     try {
-        const full = path.join(cwd, relPath);
         const stat = await fs.stat(full);
         if (stat.size > MAX_TEXT_BYTES) {
             return { oldText: '', newText: '', isBinary: false, tooLarge: true };