fix(sea): files inside symlinks are not resolved correctly (#295)

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;
     }

test/test-99-#295/index.js

@@ -0,0 +1,5 @@
+'use strict';
+
+const log = require('./lib/log');
+
+log(42);

test/test-99-#295/lib

@@ -0,0 +1 @@
+./reallib

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 });

test/test-99-#295/package.json

@@ -0,0 +1,6 @@
+{
+  "name": "test-99-#295",
+  "version": "1.0.0",
+  "main": "index.js",
+  "bin": "index.js"
+}

test/test-99-#295/reallib/log.js

@@ -0,0 +1,3 @@
+'use strict';
+
+module.exports = console.log;