@@ -250,11 +250,9 @@ static int win_path_init(win_path_t *result, const wchar_t *path) {
         return 0;
     }
 
-    DWORD full_size = GetFullPathNameW(path, 0, NULL, NULL);
-    if (full_size == 0) {
-        // Let the actual filesystem operation report the error for this path.
-        return 0;
-    }
+    // GetFullPathNameW can reject a zero-sized probe for long paths when process-wide long-path
+    // support is unavailable, so begin with MAX_PATH and grow from its insufficient-buffer result.
+    DWORD full_size = MAX_PATH;
     wchar_t *full_path = NULL;
     DWORD full_len;
     for (;;) {
@@ -292,6 +290,12 @@ static int win_path_init(win_path_t *result, const wchar_t *path) {
         return 0;
     }
 
+    if (full_len >= 4 && full_path[0] == L'\\' && full_path[1] == L'\\' && full_path[2] == L'?' && full_path[3] == L'\\') {
+        result->value = full_path;
+        result->allocated = full_path;
+        return 0;
+    }
+
     const wchar_t *prefix;
     size_t prefix_len;
     size_t source_offset;