diff-lib: tighten show_interdiff()'s interface

To compute and show an interdiff, show_interdiff() needs only the two
OID's to compare and a diffopts, yet it expects callers to supply an
entire rev_info. The demand for rev_info is not only overkill, but also
places unnecessary burden on potential future callers which might not
otherwise have a rev_info at hand. Address this by tightening its
signature to require only the items it needs instead of a full rev_info.

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 6 insertions, 1 deletions

diff --git a/diff.h b/diff.h
index 308937c..49242d2 100644
--- a/diff.h
+++ b/diff.h
@@ -600,7 +600,12 @@ int index_differs_from(struct repository *r, const char *def,
 		       const struct diff_flags *flags,
 		       int ita_invisible_in_index);
 
-void show_interdiff(struct rev_info *, int indent);
+/*
+ * Emit an interdiff of two object ID's to 'diff_options.file' optionally
+ * indented by 'indent' spaces.
+ */
+void show_interdiff(const struct object_id *, const struct object_id *,
+		    int indent, struct diff_options *);
 
 /*
  * Fill the contents of the filespec "df", respecting any textconv defined by