Steps to reproduce:

• Create first version of a page
• Delete this page
• Create page again
• Restore very first version
• Purge (Otherwise the very first version is not shown in the history)

Result: Diff-Size equals History-Size of second version
E.g. "32 bytes after change" (+32)

Expected Result: Diff-Size is recalculated
E.g. "0 bytes after change" (0)

Test instance: https://commons.wikimedia.org/w/index.php?title=User:McZusatz/test&action=history

Version: 1.23.0
Severity: normal