[tracker/tracker-0.10: 29/32] libtracker-extract: Do some basic checks for GPS coordinates in EXIF tags

[Martyn James Russell <mr src gnome org>]

commit 15d60186896a27b26f46572709eef7904bfd7ace
Author: Carlos Garnacho <carlos lanedo com>
Date:   Fri Jun 24 17:14:38 2011 +0200

    libtracker-extract: Do some basic checks for GPS coordinates in EXIF tags
    
    On some photos it would get the ExifEntries, but the coordinates wouldn't
    be meaningful, so at least check the rational numbers' denominators to
    avoid division by zero.

 src/libtracker-extract/tracker-exif.c |   15 ++++++++++++++-
 1 files changed, 14 insertions(+), 1 deletions(-)
---
diff --git a/src/libtracker-extract/tracker-exif.c b/src/libtracker-extract/tracker-exif.c
index 37fd810..280621e 100644
--- a/src/libtracker-extract/tracker-exif.c
+++ b/src/libtracker-extract/tracker-exif.c
@@ -297,7 +297,14 @@ get_gps_coordinate (ExifData *exif,
 		c2 = exif_get_rational (entry->data+8, order);
 		c3 = exif_get_rational (entry->data+16, order);
 		ref = exif_get_short (refentry->data, order);
-		
+
+		/* Avoid ridiculous values */
+		if (c1.denominator == 0 ||
+		    c2.denominator == 0 ||
+		    c3.denominator == 0) {
+			return NULL;
+		}
+
 		f = (double)c1.numerator/c1.denominator+
 		    (double)c2.numerator/(c2.denominator*60)+
 		    (double)c3.numerator/(c3.denominator*60*60);
@@ -327,6 +334,12 @@ get_gps_altitude (ExifData *exif,
 
 		order = exif_data_get_byte_order (exif);
 		c = exif_get_rational (entry->data, order);
+
+		/* Avoid ridiculous values */
+		if (c.denominator == 0) {
+			return NULL;
+		}
+
 		f = (double)c.numerator/c.denominator;
 
 		/* Strictly speaking it is invalid not to have this