fix(server): retain literal symlink targets in Git event identity

Canonical realpaths can erase a symlink target spelling when its parent is also a symlink, such as /var on macOS. Resolve these aliases once during setup so deleted and ignored event paths still match without per-event IO.

packages/server/src/server/git-observation-paths.ts

@@ -1,7 +1,8 @@
 import { realpath } from "node:fs";
+import { readlink } from "node:fs/promises";
 import { promisify } from "node:util";
 import pLimit from "p-limit";
-import { sep } from "node:path";
+import { dirname, resolve as resolvePath, sep } from "node:path";
 import { looksLikeDefiniteWindowsPath, normalizePathPreservingCase } from "../utils/path.js";
 
 const nativeRealpath = promisify(realpath.native);
@@ -31,6 +32,22 @@ export class GitObservationPaths {
         /* Missing roots retain lexical identity. */
       }
     }
+    // A link may name /var/... while realpath returns /private/var/... on macOS.
+    // Retain literal targets too, including chains, without following links in callbacks.
+    let current = root;
+    const visited = new Set<string>();
+    for (let remaining = 40; remaining > 0; remaining--) {
+      const alias = normalizePath(current);
+      if (visited.has(alias)) break;
+      visited.add(alias);
+      aliases.add(alias);
+      try {
+        const target = await identityIo(() => readlink(current));
+        current = resolvePath(dirname(current), target);
+      } catch {
+        break;
+      }
+    }
     return new GitObservationPaths(root, [...aliases], windows);
   }
 

packages/server/src/server/workspace-git-service.observation.integration.test.ts

@@ -671,3 +671,27 @@ test("concurrent alias requests establish one working-tree subscription", async
     rmSync(root, { recursive: true, force: true });
   }
 });
+
+test("Git event identity retains a symlink's literal target before canonicalizing its parent", async () => {
+  const { mkdir, symlink } = await import("node:fs/promises");
+  const { GitObservationPaths } = await import("./git-observation-paths.js");
+  const root = realpathSync(mkdtempSync(path.join(tmpdir(), "git-observation-literal-target-")));
+  const repository = path.join(root, "repository");
+  const parentAlias = path.join(root, "parent-alias");
+  const workspaceAlias = path.join(root, "workspace-alias");
+  const literalTarget = path.join(parentAlias, "repository");
+  const linkType = process.platform === "win32" ? "junction" : "dir";
+  try {
+    await mkdir(repository);
+    await symlink(root, parentAlias, linkType);
+    await symlink(literalTarget, workspaceAlias, linkType);
+    const paths = await GitObservationPaths.create(workspaceAlias);
+    const accept = paths.createEventFilter([path.join(workspaceAlias, "ignored")]);
+    for (const spelling of [workspaceAlias, literalTarget, repository]) {
+      expect(paths.relative(path.join(spelling, "deleted.txt"))).toBe("deleted.txt");
+      expect(accept(path.join(spelling, "ignored", "deleted.txt"))).toBe(false);
+    }
+  } finally {
+    rmSync(root, { recursive: true, force: true });
+  }
+});