[tracker] tracker-extract, mp3: Add comment and fix size param of get_encoding

[Philip Van Hoof <pvanhoof src gnome org>]

commit a7e88bea7f0885a35ddbe1a98e589e7a44b9ccf7
Author: Philip Van Hoof <philip codeminded be>
Date:   Fri Mar 4 14:09:04 2011 +0100

    tracker-extract,mp3: Add comment and fix size param of get_encoding

 src/tracker-extract/tracker-extract-mp3.c |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)
---
diff --git a/src/tracker-extract/tracker-extract-mp3.c b/src/tracker-extract/tracker-extract-mp3.c
index 93ccc4d..0c56894 100644
--- a/src/tracker-extract/tracker-extract-mp3.c
+++ b/src/tracker-extract/tracker-extract-mp3.c
@@ -740,13 +740,14 @@ get_id3 (const gchar *data,
 		gboolean encoding_was_found;
 
 		/* Get the encoding for ALL the data we are extracting here */
-
+		/* This wont work with encodings where a NUL byte may be actually valid,
+		 * like UTF-16 */
 		s = g_string_new_len (pos, strnlen (pos, 30));
 		g_string_append_len (s, pos + 30, strnlen (pos+30, 30));
 		g_string_append_len (s, pos + 60, strnlen (pos+60, 30));
 		g_string_append_len (s, pos + 94, strnlen (pos+94, ((pos+94)[28] != 0) ? 30 : 28));
 
-		encoding = get_encoding (s->str, 90, &encoding_was_found);
+		encoding = get_encoding (s->str, s->len, &encoding_was_found);
 
 		if (encoding_was_found) {
 			id3->encoding = g_strdup (encoding);