[tracker] tracker-extract: Fix checks for exif read API and add some for iptc

[Martyn James Russell <mr src gnome org>]

commit adad4cec018f4f1caedee6d02a253fb44e1d048c
Author: Martyn Russell <martyn lanedo com>
Date:   Mon Jan 18 12:17:18 2010 +0000

    tracker-extract: Fix checks for exif read API and add some for iptc

 src/tracker-extract/tracker-exif.c |    3 ++-
 src/tracker-extract/tracker-iptc.c |    2 ++
 2 files changed, 4 insertions(+), 1 deletions(-)
---
diff --git a/src/tracker-extract/tracker-exif.c b/src/tracker-extract/tracker-exif.c
index bb4e096..e373de6 100644
--- a/src/tracker-extract/tracker-exif.c
+++ b/src/tracker-extract/tracker-exif.c
@@ -307,8 +307,9 @@ tracker_exif_read (const unsigned char *buffer,
                    TrackerExifData     *data)
 {
 	g_return_val_if_fail (buffer != NULL, FALSE);
-	g_return_val_if_fail (len < 1, FALSE);
+	g_return_val_if_fail (len > 0, FALSE);
 	g_return_val_if_fail (uri != NULL, FALSE);
+	g_return_val_if_fail (data != NULL, FALSE);
 	
 #ifdef HAVE_LIBEXIF
 	ExifData *exif;
diff --git a/src/tracker-extract/tracker-iptc.c b/src/tracker-extract/tracker-iptc.c
index b32043e..4ad1675 100644
--- a/src/tracker-extract/tracker-iptc.c
+++ b/src/tracker-extract/tracker-iptc.c
@@ -153,7 +153,9 @@ tracker_iptc_read (const unsigned char *buffer,
                    TrackerIptcData     *data)
 {
 	g_return_val_if_fail (buffer != NULL, FALSE);
+	g_return_val_if_fail (len > 0, FALSE);
 	g_return_val_if_fail (uri != NULL, FALSE);
+	g_return_val_if_fail (data != NULL, FALSE);
 
 #ifdef HAVE_LIBIPTCDATA
 	IptcData *iptc;