shell completion --format: work with nil structs

AutocompleteFormat() takes the format struct as argument. Often the structs
are deeply nested and contain other structs. Up until now if there was a
pointer to a struct the logic was not able to get the field names from
that, simply because the pointer was nil. However it is possible to
create a new initialized type with reflect.New(). This allows us to
complete all struct fields/functions even when there nil pointers.
Therefore we can drop the extra initialization which was done by some
callers.

Signed-off-by: Paul Holzinger <pholzing@redhat.com>

1 files changed, 9 insertions, 5 deletions

diff --git a/cmd/podman/common/completion_test.go b/cmd/podman/common/completion_test.go
index d28ac3928..bfff9a96e 100644
--- a/cmd/podman/common/completion_test.go
+++ b/cmd/podman/common/completion_test.go
@@ -34,10 +34,9 @@ func TestAutocompleteFormat(t *testing.T) {
 		Name string
 		Age  int
 		Car  *Car
+		Car2 *Car
 		*Anonymous
-	}{
-		Anonymous: &Anonymous{},
-	}
+	}{}
 
 	testStruct.Car = &Car{}
 	testStruct.Car.Extras = map[string]string{"test": "1"}
@@ -80,12 +79,12 @@ func TestAutocompleteFormat(t *testing.T) {
 		{
 			"fist level struct field name",
 			"{{.",
-			[]string{"{{.Name}}", "{{.Age}}", "{{.Car.", "{{.Anonymous.", "{{.Hello}}"},
+			[]string{"{{.Name}}", "{{.Age}}", "{{.Car.", "{{.Car2.", "{{.Anonymous.", "{{.Hello}}"},
 		},
 		{
 			"fist level struct field name",
 			"{{ .",
-			[]string{"{{ .Name}}", "{{ .Age}}", "{{ .Car.", "{{ .Anonymous.", "{{ .Hello}}"},
+			[]string{"{{ .Name}}", "{{ .Age}}", "{{ .Car.", "{{ .Car2.", "{{ .Anonymous.", "{{ .Hello}}"},
 		},
 		{
 			"fist level struct field name",
@@ -103,6 +102,11 @@ func TestAutocompleteFormat(t *testing.T) {
 			[]string{"{{ .Car.Brand}}"},
 		},
 		{
+			"second level nil struct field name",
+			"{{ .Car2.",
+			[]string{"{{ .Car2.Brand}}", "{{ .Car2.Stats.", "{{ .Car2.Extras}}", "{{ .Car2.Color}}", "{{ .Car2.Type}}"},
+		},
+		{
 			"three level struct field name",
 			"{{ .Car.Stats.",
 			[]string{"{{ .Car.Stats.HP}}", "{{ .Car.Stats.Displacement}}"},