## Summary
When comparing branches with **no common merge base** (e.g. unrelated
histories or orphan branches), `PageIsComparePull` is false and
`CommitCount` is zero. The compare template still showed
`repo.commits.nothing_to_compare`, which in German reads like the
branches are identical—even though the flash already explains there is
no merge base.
## Changes
- **`templates/repo/diff/compare.tmpl`**: Only render the grey “nothing
to compare” segment when `CompareInfo.CompareBase` is set.
<img width="1962" height="564"
src="https://github.com/user-attachments/assets/adc3b4a0-6f03-45da-b297-e15e5ad0aa79"
/>
Fixes#37642
---------
Signed-off-by: Nicolas <bircni@icloud.com>
de290f2121