update: return failure if any mirror update failed

fixes #4040

src/apk_database.h

@@ -148,6 +148,7 @@ struct apk_database {
 	char *cache_remount_dir;
 	apk_blob_t *arch;
 	unsigned int local_repos, available_repos;
+	int repo_update_errors;
 	unsigned int pending_triggers;
 	int performing_self_update : 1;
 	int permanent : 1;

src/database.c

@@ -2017,8 +2017,10 @@ static int apk_repository_update(struct apk_database *db, struct apk_repository
 	int r, verify = (apk_flags & APK_ALLOW_UNTRUSTED) ? APK_SIGN_NONE : APK_SIGN_VERIFY;
 
 	r = apk_cache_download(db, repo, NULL, verify, NULL, NULL);
-	if (r != 0)
+	if (r != 0) {
 		apk_error("%s: %s", repo->url, apk_error_str(r));
+		db->repo_update_errors++;
+	}
 
 	return r;
 }

src/update.c

@@ -20,6 +20,7 @@ static int update_main(void *ctx, struct apk_database *db, struct apk_string_arr
 {
 	struct apk_repository *repo;
 	int i;
+	char buf[32] = "OK:";
 
 	if (apk_verbosity < 1)
 		return 0;
@@ -35,10 +36,13 @@ static int update_main(void *ctx, struct apk_database *db, struct apk_string_arr
 			    db->repos[i].url);
 	}
 
-	apk_message("OK: %d distinct packages available",
+	if (db->repo_update_errors != 0)
+		snprintf(buf, sizeof(buf), "%d errors;",
+			 db->repo_update_errors);
+	apk_message("%s %d distinct packages available", buf,
 		db->available.packages.num_items);
 
-	return 0;
+	return db->repo_update_errors;
 }
 
 static struct apk_applet apk_update = {