From af53198f0c7b597fc1376261298f980add9b25d3 Mon Sep 17 00:00:00 2001
From: Enrico Tassi <enrico.tassi@inria.fr>
Date: Thu, 23 Mar 2006 09:06:06 +0000
Subject: [PATCH] fix

---
 matita/scripts/crontab.sh | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/matita/scripts/crontab.sh b/matita/scripts/crontab.sh
index 99b4a13a6..64708ba77 100644
--- a/matita/scripts/crontab.sh
+++ b/matita/scripts/crontab.sh
@@ -47,7 +47,23 @@ fi
 CUR_TIME=`echo $SQLQTIME$MARK$SQLQGRMARK | $MYSQL`
 OLD_TIME=`echo $SQLQTIME$LASTMARK$SQLQGRMARK | $MYSQL`
 
-((DELTA=$CUR_CENTS-$OLD_CENTS))
+if [ -z "$CUR_TIME" -o -z "$OLD_TIME"]; then
+    cat <<EOT
+
+    Unable to calculate total time amounts:
+    
+      $SQLQTIME$MARK$SQLQGRMARK 
+      
+    or
+
+      $SQLQTIME$LASTMARK$SQLQGRMARK
+      
+    gave an empty result
+    
+EOT
+fi
+
+((DELTA=$CUR_TIME-$OLD_TIME))
 if [ $DELTA -lt 0 ]; then
   PERC=0
 else
-- 
2.39.2