Fix default values for custom fields

Fallback to the original default detection logic if we have an unknown
type.

Fixes #91

1 files changed, 11 insertions, 1 deletions

diff --git a/flag.go b/flag.go
index c28f3bd..b0b0d46 100644
--- a/flag.go
+++ b/flag.go
@@ -437,7 +437,17 @@ func (f *Flag) defaultIsZeroValue() bool {
 	case *intSliceValue, *stringSliceValue, *stringArrayValue:
 		return f.DefValue == "[]"
 	default:
-		return true
+		switch f.Value.String() {
+		case "false":
+			return true
+		case "<nil>":
+			return true
+		case "":
+			return true
+		case "0":
+			return true
+		}
+		return false
 	}
 }