Restore readonly bit if rename fails

nojb · nojb · commit cd930ded34a8 · 2026-03-03T11:30:39.000+01:00
diff --git a/runtime/win32.c b/runtime/win32.c
@@ -799,14 +799,14 @@ int caml_win32_rename(const wchar_t * oldpath, const wchar_t * newpath)
     errno = ENOTDIR;
     return -1;
   }
-
   /* Another cornercase not handled by MoveFileEx:
      - file to existing read-only file - should succeed
      remove read-only bit before trying to rename */
+  BOOL removed_readonly = FALSE;
   if (check_attr(new_attribs, FILE_ATTRIBUTE_READONLY, TRUE)) {
-    SetFileAttributes(newpath, new_attribs & ~FILE_ATTRIBUTE_READONLY);
+    removed_readonly =
+      SetFileAttributes(newpath, new_attribs & ~FILE_ATTRIBUTE_READONLY);
   }
-
   /* MOVEFILE_REPLACE_EXISTING: to be closer to POSIX
      MOVEFILE_COPY_ALLOWED: MoveFile performs a copy if old and new
        paths are on different devices, so we do the same here for
@@ -832,7 +832,10 @@ int caml_win32_rename(const wchar_t * oldpath, const wchar_t * newpath)
       return 0;
     }
   }
-
+  if (removed_readonly) {
+    /* Restore read-only bit if we failed to rename. */
+    SetFileAttributes(newpath, new_attribs);
+  }
   errno = caml_posixerr_of_win32err(GetLastError());
   if (errno == 0) errno = EINVAL;
   return -1;
