OO-1305: add ArithmeticException to the list of catched exceptions

src/main/java/org/olat/course/condition/_i18n/LocalStrings_de.properties

@@ -18,6 +18,7 @@ error.fewerargs=Die "{0}"-Funktion hat weniger Argumente.
 ##<OLATCE-1088>
 error.argtype.outcome.undefined=Die angeforderte Ergebnisvariable existiert im ausgew\u00e4hlten Test nicht!
 ##</OLATCE-1088>
+error.divide.by.zero=Die Regel kann zu ein "Division durch 0" Fehler f\u00FChren.
 error.fix=Erstellen
 error.illegal.operation.at=Die Operation bei  Zeichen {0} ist nicht erlaubt, konsultieren Sie die Hilfe f\u00FCr m\u00F6gliche Operationen.
 error.inexpression.at=Der Bedingungsausdruck hat einen Fehler an der Position {0}.

src/main/java/org/olat/course/condition/_i18n/LocalStrings_en.properties

@@ -18,6 +18,7 @@ error.fewerargs=The "{0}" function has fewer arguments than specified.
 ##<OLATCE-1088>
 error.argtype.outcome.undefined=The requested outcome-variable does not exist in the given test!
 ##</OLATCE-1088>
+error.divide.by.zero=The rule can produce "divided by 0" errors.
 error.fix=Create
 error.illegal.operation.at=The operation at position {0} is not allowed, see Help for possible operations.
 error.inexpression.at=This condition expression has an error at position {0}.

src/main/java/org/olat/course/condition/interpreter/ConditionInterpreter.java

@@ -268,6 +268,9 @@ public class ConditionInterpreter {
 			// messages (translation keys)
 			msg = "error.undefined.variable.at";
 			params = new String[]{};
+		} catch(ArithmeticException aex) {
+			msg = "error.divide.by.zero";
+			params = new String[]{};
 		} catch (Exception ex) {
 			// this must not happen!
 			throw new OLATRuntimeException(ex.getMessage(), ex);