From 843326bf87ac2679bf3d3c41ea5fb551b7878e55 Mon Sep 17 00:00:00 2001
From: Michael Potthoff <michael@potthoff.eu>
Date: Fri, 21 Aug 2026 00:28:44 +0200
Subject: [PATCH] fix(sea): files inside symlinks are not resolved correctly
 (#295)

---
 prelude/sea-vfs-setup.js         | 25 ++++++++++++++++++++-----
 test/test-99-#295/index.js       |  5 +++++
 test/test-99-#295/lib            |  1 +
 test/test-99-#295/main.js        | 31 +++++++++++++++++++++++++++++++
 test/test-99-#295/package.json   |  6 ++++++
 test/test-99-#295/reallib/log.js |  3 +++
 6 files changed, 66 insertions(+), 5 deletions(-)
 create mode 100644 test/test-99-#295/index.js
 create mode 120000 test/test-99-#295/lib
 create mode 100644 test/test-99-#295/main.js
 create mode 100644 test/test-99-#295/package.json
 create mode 100644 test/test-99-#295/reallib/log.js

diff --git a/prelude/sea-vfs-setup.js b/prelude/sea-vfs-setup.js
index 94a34ea58..48018d820 100644
--- a/prelude/sea-vfs-setup.js
+++ b/prelude/sea-vfs-setup.js
@@ -307,6 +307,10 @@ class SEAProvider extends MemoryProvider {
     this._manifest = seaManifest;
     this._fileCache = new Map();
 
+    // Precompute whether the manifest has any symlinks.
+    // If a project has no symlinks, there is also no need to resolve them.
+    this._hasSymlinks = Object.keys(seaManifest.symlinks).length > 0;
+
     // Pick the per-file decompressor once at construction time.  Absent or 0 =
     // uncompressed archive (backward compat with pre-#250 SEA binaries).  The
     // shared helper raises a uniformly-worded error when the host Node.js is
@@ -337,15 +341,26 @@ class SEAProvider extends MemoryProvider {
   }
 
   _resolveSymlink(p) {
-    // Fast path: the vast majority of lookups (~30K per startup on large
-    // projects) are not symlinks. A single object-has-key check avoids
-    // entering the loop and the i++/target fetch overhead for the common
-    // case.
+    // Fast path: if the manifest has no symlinks, skip the loop entirely.
+    if (!this._hasSymlinks) return p;
     var symlinks = this._manifest.symlinks;
-    if (symlinks[p] === undefined) return p;
     var original = p;
     for (var i = 0; i < MAX_SYMLINK_DEPTH; i++) {
+      // First check the full path, then walk up the directory tree to find a symlink.
       var target = symlinks[p];
+      if (!target) {
+        var parentIdx = p.lastIndexOf('/');
+        while (parentIdx > 0) {
+          var parent = p.slice(0, parentIdx);
+          target = symlinks[parent];
+          if (target) {
+            // Resolve the symlink and append the remainder of the original path.
+            target = target + p.slice(parentIdx);
+            break;
+          }
+          parentIdx = parent.lastIndexOf('/');
+        }
+      }
       if (!target) return p;
       p = target;
     }
diff --git a/test/test-99-#295/index.js b/test/test-99-#295/index.js
new file mode 100644
index 000000000..960ef24a6
--- /dev/null
+++ b/test/test-99-#295/index.js
@@ -0,0 +1,5 @@
+'use strict';
+
+const log = require('./lib/log');
+
+log(42);
diff --git a/test/test-99-#295/lib b/test/test-99-#295/lib
new file mode 120000
index 000000000..7b6a06f01
--- /dev/null
+++ b/test/test-99-#295/lib
@@ -0,0 +1 @@
+./reallib
\ No newline at end of file
diff --git a/test/test-99-#295/main.js b/test/test-99-#295/main.js
new file mode 100644
index 000000000..d8592e8de
--- /dev/null
+++ b/test/test-99-#295/main.js
@@ -0,0 +1,31 @@
+#!/usr/bin/env node
+
+'use strict';
+
+const assert = require('assert');
+const utils = require('../utils.js');
+
+// Enhanced SEA requires Node.js >= 22
+if (utils.getNodeMajorVersion() < 22) {
+  return;
+}
+
+assert(__dirname === process.cwd());
+
+// test symlinks on unix only // TODO junction
+if (process.platform === 'win32') return;
+
+const input = './package.json';
+const testName = 'test-99-#295';
+
+const newcomers = utils.seaHostOutputs(testName);
+
+const before = utils.filesBefore(newcomers);
+
+utils.runSeaHostOnly(input, testName);
+
+const expectedOutput = '42\n';
+
+utils.assertSeaOutput(testName, expectedOutput);
+
+utils.filesAfter(before, newcomers, { tolerateWindowsEbusy: true });
diff --git a/test/test-99-#295/package.json b/test/test-99-#295/package.json
new file mode 100644
index 000000000..a06b50260
--- /dev/null
+++ b/test/test-99-#295/package.json
@@ -0,0 +1,6 @@
+{
+  "name": "test-99-#295",
+  "version": "1.0.0",
+  "main": "index.js",
+  "bin": "index.js"
+}
diff --git a/test/test-99-#295/reallib/log.js b/test/test-99-#295/reallib/log.js
new file mode 100644
index 000000000..2e92b2d93
--- /dev/null
+++ b/test/test-99-#295/reallib/log.js
@@ -0,0 +1,3 @@
+'use strict';
+
+module.exports = console.log;