Merge pull request #20904 from hashicorp/jbardin/filter-shim-nulls

filter nulls when shimming a config

config/hcl2shim/values.go

@@ -167,7 +167,10 @@ func ConfigValueFromHCL2(v cty.Value) interface{} {
 		it := v.ElementIterator()
 		for it.Next() {
 			_, ev := it.Element()
-			l = append(l, ConfigValueFromHCL2(ev))
+			cv := ConfigValueFromHCL2(ev)
+			if cv != nil {
+				l = append(l, cv)
+			}
 		}
 		return l
 	}

config/hcl2shim/values_test.go

@@ -232,6 +232,26 @@ func TestConfigValueFromHCL2Block(t *testing.T) {
 			&configschema.Block{},
 			nil,
 		},
+		// nulls should be filtered out of the config, since they couldn't exist
+		// in hcl.
+		{
+			cty.ObjectVal(map[string]cty.Value{
+				"list": cty.ListVal([]cty.Value{
+					cty.StringVal("ok"),
+					cty.NullVal(cty.String)}),
+			}),
+			&configschema.Block{
+				Attributes: map[string]*configschema.Attribute{
+					"list": {
+						Type:     cty.List(cty.String),
+						Optional: true,
+					},
+				},
+			},
+			map[string]interface{}{
+				"list": []interface{}{"ok"},
+			},
+		},
 	}
 
 	for _, test := range tests {