[chronojump] Fixed crash on no duration defined on networks 3.1 tasks definition

[Xavier de Blas <xaviblas src gnome org>]

commit c85cf98a4e4109c71771b41cdf0fe638b8e5de88
Author: Xavier de Blas <xaviblas gmail com>
Date:   Wed Dec 1 16:56:59 2021 +0100

    Fixed crash on no duration defined on networks 3.1 tasks definition

 src/json/compujumpOther.cs | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)
---
diff --git a/src/json/compujumpOther.cs b/src/json/compujumpOther.cs
index c7ac9c249..9431eb383 100644
--- a/src/json/compujumpOther.cs
+++ b/src/json/compujumpOther.cs
@@ -85,12 +85,16 @@ public class TaskEncoder : Task
                ExerciseId = jsonTask ["exercise_id"];
                ExerciseName = jsonTask ["exercise_name"];
 
-               string NrepsStr = jsonTask ["duration"]; //eg: "15 Repetitions"
-               Match match = Regex.Match(NrepsStr, @"(\d+) Repetitions");
-               //LogB.Information(string.Format("NrepsStr: {0}, match.Groups.Count: {1}, 
match.Groups[1].Value: {2}",
-               //      NrepsStr, match.Groups.Count, match.Groups[1].Value));
-               if(match.Groups.Count == 2 && Util.IsNumber(match.Groups[1].Value, false))
-                       Nreps = Convert.ToInt32(match.Groups[1].Value);
+               if(jsonTask ["duration"] == null) //fix if duration is not defined
+                       Nreps = -1;
+               else {
+                       string NrepsStr = jsonTask ["duration"]; //eg: "15 Repetitions"
+                       Match match = Regex.Match(NrepsStr, @"(\d+) Repetitions");
+                       //LogB.Information(string.Format("NrepsStr: {0}, match.Groups.Count: {1}, 
match.Groups[1].Value: {2}",
+                       //      NrepsStr, match.Groups.Count, match.Groups[1].Value));
+                       if(match.Groups.Count == 2 && Util.IsNumber(match.Groups[1].Value, false))
+                               Nreps = Convert.ToInt32(match.Groups[1].Value);
+               }
 
                Laterality = jsonTask ["laterality"];
                Sets = jsonTask ["sets"];