transport: allow summary-width to be computed dynamically

Now we have identified three callchains that have a set of refs that
they want to show their <old, new> object names in an aligned output,
we can replace their reference to the constant TRANSPORT_SUMMARY_WIDTH
with a helper function call to transport_summary_width() that takes
the set of ref as a parameter.  This step does not yet iterate over
the refs and compute, which is left as an exercise to the readers.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/fetch.c

@@ -722,7 +722,7 @@ static int store_updated_refs(const char *raw_url, const char *remote_name,
 	char *url;
 	const char *filename = dry_run ? "/dev/null" : git_path_fetch_head();
 	int want_status;
-	int summary_width = TRANSPORT_SUMMARY_WIDTH;
+	int summary_width = transport_summary_width(ref_map);
 
 	fp = fopen(filename, "a");
 	if (!fp)
@@ -906,7 +906,7 @@ static int prune_refs(struct refspec *refs, int ref_count, struct ref *ref_map,
 	int url_len, i, result = 0;
 	struct ref *ref, *stale_refs = get_stale_heads(refs, ref_count, ref_map);
 	char *url;
-	int summary_width = TRANSPORT_SUMMARY_WIDTH;
+	int summary_width = transport_summary_width(stale_refs);
 	const char *dangling_msg = dry_run
 		? _("   (%s will become dangling)")
 		: _("   (%s has become dangling)");

transport.c

@@ -429,6 +429,11 @@ static int print_one_push_status(struct ref *ref, const char *dest, int count,
 	return 1;
 }
 
+int transport_summary_width(const struct ref *refs)
+{
+	return (2 * FALLBACK_DEFAULT_ABBREV + 3);
+}
+
 void transport_print_push_status(const char *dest, struct ref *refs,
 				  int verbose, int porcelain, unsigned int *reject_reasons)
 {
@@ -436,7 +441,7 @@ void transport_print_push_status(const char *dest, struct ref *refs,
 	int n = 0;
 	unsigned char head_sha1[20];
 	char *head;
-	int summary_width = TRANSPORT_SUMMARY_WIDTH;
+	int summary_width = transport_summary_width(refs);
 
 	head = resolve_refdup("HEAD", RESOLVE_REF_READING, head_sha1, NULL);
 

transport.h

@@ -142,7 +142,7 @@ struct transport {
 #define TRANSPORT_PUSH_ATOMIC 8192
 #define TRANSPORT_PUSH_OPTIONS 16384
 
-#define TRANSPORT_SUMMARY_WIDTH (2 * FALLBACK_DEFAULT_ABBREV + 3)
+extern int transport_summary_width(const struct ref *refs);
 
 /* Returns a transport suitable for the url */
 struct transport *transport_get(struct remote *, const char *);