57_Calendar: catch deadly regular expressions in get

git-svn-id: svn://svn.code.sf.net/p/fhem/code/trunk@8644 2b470e98-0d58-463d-a4d8-8e2adae1ed80

fhem/FHEM/57_Calendar.pm

@@ -1076,9 +1076,13 @@ sub Calendar_Get($@) {
     return "argument is missing" if($#a != 2);
     my $regexp= $a[2];
     my @uids;
+    eval {
         foreach my $event ($eventsObj->events()) {
             push @uids, $event->uid() if($event->summary() =~ m/$regexp/);
         }
+    };
+    Log3($hash, 2, "Calendar " . $hash->{NAME} . 
+        ": The regular expression $regexp caused a problem: $@") if($@);
     return join(";", @uids);
   
   } else {