fix: swap High/Low in BasePermissions.set() and has()

self.High was storing Low bits (0-31) and self.Low was storing
High bits (32-63), causing to_json() to serialize values into
the wrong SharePoint API fields.

Fixed by swapping the assignments in set() and the checks in
has() so that names match the SharePoint convention:
  - Low = bits 0-31
  - High = bits 32-63

to_json() and set_property() need no changes.

Fixes #959

Author: Vadim Gremyachev

office365/sharepoint/permissions/base_permissions.py

@@ -42,9 +42,9 @@ def set(self, perm: Union[PermissionKind, int]) -> None:
             bit_pos = perm.value - 1
             mask = 1 << (bit_pos % self._BITS_PER_INT)
             if bit_pos < self._BITS_PER_INT:
-                self.High |= mask
-            elif self._BITS_PER_INT <= bit_pos < self._MAX_BITS:
                 self.Low |= mask
+            elif self._BITS_PER_INT <= bit_pos < self._MAX_BITS:
+                self.High |= mask
 
     def has(self, perm: Union[PermissionKind, int]) -> bool:
         """Checks if permission is set with support for both enum and integer values."""
@@ -58,7 +58,7 @@ def has(self, perm: Union[PermissionKind, int]) -> bool:
         if not 0 <= bit_pos < self._MAX_BITS:
             return False
         mask = 1 << (bit_pos % self._BITS_PER_INT)
-        return bool(self.High & mask) if bit_pos < self._BITS_PER_INT else bool(self.Low & mask)
+        return bool(self.Low & mask) if bit_pos < self._BITS_PER_INT else bool(self.High & mask)
 
     def clear_all(self):
         """Clears all permissions for the current instance."""