[evolution-ews] Make get_folders() method cope with "" as 'top' argument, as well as NULL

[David Woodhouse <dwmw2 src gnome org>]

commit 28b3dac90e4fa58091270e0f772f6209c8b122d4
Author: David Woodhouse <David Woodhouse intel com>
Date:   Fri Jul 1 23:10:55 2011 +0100

    Make get_folders() method cope with "" as 'top' argument, as well as NULL

 src/camel/camel-ews-store-summary.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/src/camel/camel-ews-store-summary.c b/src/camel/camel-ews-store-summary.c
index bd3697a..88e449f 100644
--- a/src/camel/camel-ews-store-summary.c
+++ b/src/camel/camel-ews-store-summary.c
@@ -638,7 +638,7 @@ camel_ews_store_summary_get_folders (CamelEwsStoreSummary *ews_summary,
 	for (i = 0; i < length; i++) {
 		if (!g_ascii_strcasecmp (groups [i], STORE_GROUP_NAME))
 			continue;
-		if (prefix) {
+		if (prefixlen) {
 			const gchar *fname = g_hash_table_lookup (ews_summary->priv->id_fname_hash, groups[i]);
 
 			if (!fname || strncmp(fname, prefix, prefixlen) ||