revset: pass an explicit `diffopts` objet to context.diff

mercurial/revset.py

@@ -33,6 +33,7 b' from . import ('
 )
 from .utils import (
     dateutil,
+    diffutil,
     stringutil,
 )
 
@@ -1803,7 +1804,8 b' def matching(repo, subset, x):'
         'phase': lambda r: repo[r].phase(),
         'substate': lambda r: repo[r].substate,
         'summary': lambda r: repo[r].description().splitlines()[0],
-        'diff': lambda r: list(repo[r].diff(opts={'git': True}),)
+        'diff': lambda r: list(repo[r].diff(
+            opts=diffutil.diffopts(repo.ui, {'git': True}))),
     }
     for info in fields:
         getfield = _funcs.get(info, None)