Refactor pretty_print_commit arguments into a struct

pretty_print_commit() has a bunch of rarely-used arguments, and
introducing more of them requires yet another update of all the call
sites.  Refactor most of them into a struct to make future extensions
easier.

The ones that stay "plain" arguments were chosen on the grounds that
all callers put real arguments there, whereas some callers have 0/NULL
for all arguments that were factored into the struct.

We declare the struct 'const' to ensure none of the callers are bitten
by the changed (no longer call-by-value) semantics.

Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 5 insertions, 2 deletions

diff --git a/builtin-merge.c b/builtin-merge.c
index b6b84286b..c69a3051f 100644
--- a/builtin-merge.c
+++ b/builtin-merge.c
@@ -264,6 +264,7 @@ static void squash_message(void)
 	struct strbuf out = STRBUF_INIT;
 	struct commit_list *j;
 	int fd;
+	struct pretty_print_context ctx = {0};
 
 	printf("Squash commit -- not updating HEAD\n");
 	fd = open(git_path("SQUASH_MSG"), O_WRONLY | O_CREAT, 0666);
@@ -285,13 +286,15 @@ static void squash_message(void)
 	if (prepare_revision_walk(&rev))
 		die("revision walk setup failed");
 
+	ctx.abbrev = rev.abbrev;
+	ctx.date_mode = rev.date_mode;
+
 	strbuf_addstr(&out, "Squashed commit of the following:\n");
 	while ((commit = get_revision(&rev)) != NULL) {
 		strbuf_addch(&out, '\n');
 		strbuf_addf(&out, "commit %s\n",
 			sha1_to_hex(commit->object.sha1));
-		pretty_print_commit(rev.commit_format, commit, &out, rev.abbrev,
-			NULL, NULL, rev.date_mode, 0);
+		pretty_print_commit(rev.commit_format, commit, &out, &ctx);
 	}
 	if (write(fd, out.buf, out.len) < 0)
 		die_errno("Writing SQUASH_MSG");