[chronojump] Fixed potentially bugs on utilDate and jumps

[Xavier de Blas <xaviblas src gnome org>]

commit 0855b07f75b7ddc3fbec17ced7d8fd86ffeb1f07
Author: Xavier de Blas <xaviblas gmail com>
Date:   Sun Jul 19 00:06:25 2020 +0200

    Fixed potentially bugs on utilDate and jumps

 src/sqlite/jump.cs | 14 ++++++++++++++
 src/utilDate.cs    |  9 ++++++++-
 2 files changed, 22 insertions(+), 1 deletion(-)
---
diff --git a/src/sqlite/jump.cs b/src/sqlite/jump.cs
index 96e650a5..7baba9ae 100644
--- a/src/sqlite/jump.cs
+++ b/src/sqlite/jump.cs
@@ -418,9 +418,23 @@ class SqliteJump : Sqlite
                  //jumps previous to DB 1.82 have no datetime on jump
                  //find session datetime for that jumps
                  if(jmp.Datetime == "")
+                 {
+                         bool found = false;
                          foreach(Session session in session_l)
+                         {
                                  if(session.UniqueID == jmp.SessionID)
+                                 {
                                          jmp.Datetime = UtilDate.ToFile(session.Date);
+                                         found = true;
+                                         break;
+                                 }
+
+                         }
+                         //on really old versions of Chronojump, deleting a session maybe does not delete 
the jumps
+                         //so could be to found a jump without a session, so assign here the MinValue 
possible of DateTime
+                         if(! found)
+                                 jmp.Datetime = UtilDate.ToFile(DateTime.MinValue);
+                 }
 
                  if(personNameInComment)
                          foreach(Person person in person_l)
diff --git a/src/utilDate.cs b/src/utilDate.cs
index 2285b9bd..8ea1f2dc 100644
--- a/src/utilDate.cs
+++ b/src/utilDate.cs
@@ -56,10 +56,17 @@ public class UtilDate
        //used also on SQL when time wants to be stored also
        public static DateTime FromFile (string s)
        {
-               //TODO: check possible errors
                string [] allFull = s.Split(new char[] {'_'});
+
+               if(allFull.Length != 2)
+                       return DateTime.MinValue;
+
                string [] dateFull = allFull[0].Split(new char[] {'-'});
                string [] timeFull = allFull[1].Split(new char[] {'-'});
+
+               if(dateFull.Length != 3 || timeFull.Length != 3)
+                       return DateTime.MinValue;
+
                return new DateTime(
                                Convert.ToInt32(dateFull[0]),
                                Convert.ToInt32(dateFull[1]),