dvdrip: Fail if we can't read the `.IFO' hash for the disc id.

This may help with the kernel reporting stale medium sizes.

diff --git a/dvdrip b/dvdrip
index 8173906..8ff1d98 100755 (executable)
--- a/dvdrip
+++ b/dvdrip
@@ -78,7 +78,7 @@ esac
 
 mkdir -p "$tmp/$tag"
 
-discid=$("$DVD_ID" "$dev")
+discid=$("$DVD_ID" -I "$dev")
 if [ -f "$tmp/$tag/discid" ]; then
   read oldid <"$tmp/$tag/discid"
   case $force,$oldid in