fs: fix cpSync handle existing symlinks

PR-URL: #58476
Fixes: #58468
Reviewed-By: Dario Piotrowicz <[email protected]>

Author: jakecastelli

lib/internal/fs/cp/cp-sync.js

@@ -196,7 +196,9 @@ function onLink(destStat, src, dest, verbatimSymlinks) {
   if (!isAbsolute(resolvedDest)) {
     resolvedDest = resolve(dirname(dest), resolvedDest);
   }
-  if (isSrcSubdir(resolvedSrc, resolvedDest)) {
+  const srcIsDir = fsBinding.internalModuleStat(src) === 1;
+
+  if (srcIsDir && isSrcSubdir(resolvedSrc, resolvedDest)) {
     throw new ERR_FS_CP_EINVAL({
       message: `cannot copy ${resolvedSrc} to a subdirectory of self ` +
           `${resolvedDest}`,

test/parallel/test-fs-cp.mjs

@@ -15,7 +15,7 @@ const {
   writeFileSync,
 } = fs;
 import net from 'net';
-import { join } from 'path';
+import { join, resolve } from 'path';
 import { pathToFileURL } from 'url';
 import { setTimeout } from 'timers/promises';
 
@@ -248,6 +248,17 @@ function nextdir(dirname) {
   );
 }
 
+// It allows copying when is not a directory
+{
+  const src = nextdir();
+  const dest = nextdir();
+  mkdirSync(src, mustNotMutateObjectDeep({ recursive: true }));
+  writeFileSync(`${src}/test.txt`, 'test');
+  symlinkSync(resolve(`${src}/test.txt`), join(src, 'link.txt'));
+  cpSync(src, dest, mustNotMutateObjectDeep({ recursive: true }));
+  cpSync(src, dest, mustNotMutateObjectDeep({ recursive: true }));
+}
+
 // It throws error if symlink in dest points to location in src.
 {
   const src = nextdir();