[tracker/tracker-0.8] Fixes GB#623836: Avoid crashing if table of pieces is empty in the msword file

[Martyn James Russell <mr src gnome org>]

commit 34f6ec0b9becaaee9f651c767b33341e74dcd66e
Author: Aleksander Morgado <aleksander lanedo com>
Date:   Thu Jul 8 17:12:30 2010 +0200

    Fixes GB#623836: Avoid crashing if table of pieces is empty in the msword file

 src/tracker-extract/tracker-extract-msoffice.c |   16 +++++++++++++---
 1 files changed, 13 insertions(+), 3 deletions(-)
---
diff --git a/src/tracker-extract/tracker-extract-msoffice.c b/src/tracker-extract/tracker-extract-msoffice.c
index c9c2de9..3e0c1ac 100644
--- a/src/tracker-extract/tracker-extract-msoffice.c
+++ b/src/tracker-extract/tracker-extract-msoffice.c
@@ -420,9 +420,11 @@ msoffice_convert_and_normalize_chunk (guint8    *buffer,
 	g_return_if_fail (p_content != NULL);
 
 	/* chunks can have different encoding
-	 *  TODO: Using g_iconv, this extra heap allocation could be
-	 *   avoided, re-using over and over again the same output buffer
-	 *   for the UTF-8 encoded string */
+	 *
+	 * TODO: Using g_iconv, this extra heap allocation could be
+	 * avoided, re-using over and over again the same output buffer
+	 * for the UTF-8 encoded string
+	 */
 	converted_text = g_convert (buffer,
 	                            chunk_size,
 	                            "UTF-8",
@@ -914,6 +916,14 @@ extract_msword_content (GsfInfile *infile,
 	gsf_input_read (document_stream, 4, tmp_buffer);
 	lcbClx = read_32bit (tmp_buffer);
 
+	/* If we got an invalid or empty length of piece table, just return
+	 * as we cannot iterate over pieces */
+	if (lcbClx <= 0) {
+		g_object_unref (document_stream);
+		g_object_unref (table_stream);
+		return NULL;
+	}
+
 	/* copy the structure holding the piece table into the clx array. */
 	clx = g_malloc (lcbClx);
 	gsf_input_seek (table_stream, fcClx, G_SEEK_SET);