GitPython: Arbitrary file overwrite via git diff --output argument injection in Diffable.diff (key- and value-controlled)

Summary Diffable.diff forwards kwargs straight into diff/difftree with no checkunsafeoptions guard. Diffable is mixed into Commit, Tree, IndexFile, and Submodule, giving a broad surface. git diff --output= writes real patch content to an attacker-chosen path, enabling arbitrary file overwrite. Ro...