Fix default values for custom fields

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

Fixes #91

1 files changed, 4 insertions, 0 deletions

diff --git a/flag_test.go b/flag_test.go
index 1befb94..b294fc7 100644
--- a/flag_test.go
+++ b/flag_test.go
@@ -891,6 +891,7 @@ const defaultOutput = `      --A                         for bootstrapping, allo
       --StringSlice stringSlice   string slice with zero default
       --Z int                     an int that defaults to zero
       --custom custom             custom Value implementation
+      --customP custom            a VarP with default (default 10)
       --maxT timeout              set timeout for dial
 `
 
@@ -934,6 +935,9 @@ func TestPrintDefaults(t *testing.T) {
 	var cv customValue
 	fs.Var(&cv, "custom", "custom Value implementation")
 
+	cv2 := customValue(10)
+	fs.VarP(&cv2, "customP", "", "a VarP with default")
+
 	fs.PrintDefaults()
 	got := buf.String()
 	if got != defaultOutput {