We currently have two different display formats in git-fetch(1) with the
"full" and "compact" formats. This is tracked with a boolean value that
simply denotes whether the display format is supposed to be compacted
or not. This works reasonably well while there are only two formats, but
we're about to introduce another format that will make this a bit more
awkward to use.

Introduce a `enum display_format` that is more readily extensible.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
---
 builtin/fetch.c | 69 +++++++++++++++++++++++++++++++++----------------
 1 file changed, 47 insertions(+), 22 deletions(-)

diff --git a/builtin/fetch.c b/builtin/fetch.c
index 007eb3693d..4c58ee503a 100644
--- a/builtin/fetch.c
+++ b/builtin/fetch.c
@@ -48,11 +48,17 @@ enum {
 	TAGS_SET = 2
 };
 
+enum display_format {
+	DISPLAY_FORMAT_UNKNOWN = 0,
+	DISPLAY_FORMAT_FULL,
+	DISPLAY_FORMAT_COMPACT,
+};
+
 struct display_state {
 	struct strbuf buf;
 
 	int refcol_width;
-	int compact_format;
+	enum display_format format;
 
 	char *url;
 	int url_len, shown_url;
@@ -820,14 +826,22 @@ static void display_state_init(struct display_state *display_state, struct ref *
 
 	git_config_get_string_tmp("fetch.output", &format);
 	if (!strcasecmp(format, "full"))
-		display_state->compact_format = 0;
+		display_state->format = DISPLAY_FORMAT_FULL;
 	else if (!strcasecmp(format, "compact"))
-		display_state->compact_format = 1;
+		display_state->format = DISPLAY_FORMAT_COMPACT;
 	else
 		die(_("invalid value for '%s': '%s'"),
 		    "fetch.output", format);
 
-	display_state->refcol_width = refcol_width(ref_map, display_state->compact_format);
+	switch (display_state->format) {
+	case DISPLAY_FORMAT_FULL:
+	case DISPLAY_FORMAT_COMPACT:
+		display_state->refcol_width = refcol_width(ref_map,
+							   display_state->format == DISPLAY_FORMAT_COMPACT);
+		break;
+	default:
+		BUG("unexpected display format %d", display_state->format);
+	}
 }
 
 static void display_state_release(struct display_state *display_state)
@@ -897,30 +911,41 @@ static void display_ref_update(struct display_state *display_state, char code,
 			       const char *remote, const char *local,
 			       int summary_width)
 {
-	int width;
-
 	if (verbosity < 0)
 		return;
 
 	strbuf_reset(&display_state->buf);
 
-	if (!display_state->shown_url) {
-		strbuf_addf(&display_state->buf, _("From %.*s\n"),
-			    display_state->url_len, display_state->url);
-		display_state->shown_url = 1;
+	switch (display_state->format) {
+	case DISPLAY_FORMAT_FULL:
+	case DISPLAY_FORMAT_COMPACT: {
+		int width;
+
+		if (!display_state->shown_url) {
+			strbuf_addf(&display_state->buf, _("From %.*s\n"),
+				    display_state->url_len, display_state->url);
+			display_state->shown_url = 1;
+		}
+
+		width = (summary_width + strlen(summary) - gettext_width(summary));
+		remote = prettify_refname(remote);
+		local = prettify_refname(local);
+
+		strbuf_addf(&display_state->buf, " %c %-*s ", code, width, summary);
+
+		if (display_state->format != DISPLAY_FORMAT_COMPACT)
+			print_remote_to_local(display_state, remote, local);
+		else
+			print_compact(display_state, remote, local);
+
+		if (error)
+			strbuf_addf(&display_state->buf, "  (%s)", error);
+
+		break;
 	}
-
-	width = (summary_width + strlen(summary) - gettext_width(summary));
-	remote = prettify_refname(remote);
-	local = prettify_refname(local);
-
-	strbuf_addf(&display_state->buf, " %c %-*s ", code, width, summary);
-	if (!display_state->compact_format)
-		print_remote_to_local(display_state, remote, local);
-	else
-		print_compact(display_state, remote, local);
-	if (error)
-		strbuf_addf(&display_state->buf, "  (%s)", error);
+	default:
+		BUG("unexpected display format %d", display_state->format);
+	};
 	strbuf_addch(&display_state->buf, '\n');
 
 	fputs(display_state->buf.buf, stderr);
-- 
2.40.1