Extract function should_expire_reflog_ent()

Extract from expire_reflog_ent() a function that is solely responsible
for deciding whether a reflog entry should be expired. By separating
this "business logic" from the mechanics of actually expiring entries,
we are working towards the goal of encapsulating reflog expiry within
the refs API, with policy decided by a callback function passed to it
by its caller.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/reflog.c

@@ -288,51 +288,65 @@ static int unreachable(struct expire_reflog_cb *cb, struct commit *commit, unsig
 	return !(commit->object.flags & REACHABLE);
 }
 
-static int expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
-		const char *email, unsigned long timestamp, int tz,
-		const char *message, void *cb_data)
+/*
+ * Return true iff the specified reflog entry should be expired.
+ */
+static int should_expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
+				    const char *email, unsigned long timestamp, int tz,
+				    const char *message, void *cb_data)
 {
 	struct expire_reflog_cb *cb = cb_data;
 	struct commit *old, *new;
 
 	if (timestamp < cb->cmd->expire_total)
-		goto prune;
-
-	if (cb->cmd->rewrite)
-		osha1 = cb->last_kept_sha1;
+		return 1;
 
 	old = new = NULL;
 	if (cb->cmd->stalefix &&
 	    (!keep_entry(&old, osha1) || !keep_entry(&new, nsha1)))
-		goto prune;
+		return 1;
 
 	if (timestamp < cb->cmd->expire_unreachable) {
 		if (cb->unreachable_expire_kind == UE_ALWAYS)
-			goto prune;
+			return 1;
 		if (unreachable(cb, old, osha1) || unreachable(cb, new, nsha1))
-			goto prune;
+			return 1;
 	}
 
 	if (cb->cmd->recno && --(cb->cmd->recno) == 0)
-		goto prune;
+		return 1;
 
-	if (cb->newlog) {
-		char sign = (tz < 0) ? '-' : '+';
-		int zone = (tz < 0) ? (-tz) : tz;
-		fprintf(cb->newlog, "%s %s %s %lu %c%04d\t%s",
-			sha1_to_hex(osha1), sha1_to_hex(nsha1),
-			email, timestamp, sign, zone,
-			message);
-		hashcpy(cb->last_kept_sha1, nsha1);
-	}
-	if (cb->cmd->verbose)
-		printf("keep %s", message);
 	return 0;
- prune:
-	if (!cb->newlog)
-		printf("would prune %s", message);
-	else if (cb->cmd->verbose)
-		printf("prune %s", message);
+}
+
+static int expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
+		const char *email, unsigned long timestamp, int tz,
+		const char *message, void *cb_data)
+{
+	struct expire_reflog_cb *cb = cb_data;
+
+	if (cb->cmd->rewrite)
+		osha1 = cb->last_kept_sha1;
+
+	if (should_expire_reflog_ent(osha1, nsha1, email, timestamp, tz,
+				     message, cb_data)) {
+		if (!cb->newlog)
+			printf("would prune %s", message);
+		else if (cb->cmd->verbose)
+			printf("prune %s", message);
+	} else {
+		if (cb->newlog) {
+			char sign = (tz < 0) ? '-' : '+';
+			int zone = (tz < 0) ? (-tz) : tz;
+			fprintf(cb->newlog, "%s %s %s %lu %c%04d\t%s",
+				sha1_to_hex(osha1), sha1_to_hex(nsha1),
+				email, timestamp, sign, zone,
+				message);
+			hashcpy(cb->last_kept_sha1, nsha1);
+		}
+		if (cb->cmd->verbose)
+			printf("keep %s", message);
+	}
 	return 0;
 }