Merge branch 'sa/multi-mailmap-fix'

When asking to apply mailmap to both author and committer field
while showing a commit object, the field that appears later was not
correctly parsed and replaced, which has been corrected.

* sa/multi-mailmap-fix:
  cat-file: fix mailmap application for different author and committer

ident.c

@@ -412,6 +412,10 @@ void apply_mailmap_to_header(struct strbuf *buf, const char **header,
 				found_header = 1;
 				buf_offset += endp - line;
 				buf_offset += rewrite_ident_line(person, endp - person, buf, mailmap);
+				/* Recompute endp after potential buffer reallocation */
+				endp = buf->buf + buf_offset;
+				if (*endp == '\n')
+					buf_offset++;
 				break;
 			}