templatefile need to be unmarked for TypeFunc

The templatefile function actually calls the full renderer within the
TypeFunc to determine what the resulting might be, but that also
requires unmarking the top-level of the vars map to strip marks even
though the value is unused.

Author: jbardin

internal/lang/funcs/filesystem.go

@@ -126,10 +126,11 @@ func MakeTemplateFileFunc(baseDir string, funcsCb func() (funcs map[string]funct
 			if err != nil {
 				return cty.DynamicPseudoType, err
 			}
+			vars, _ := args[1].UnmarkDeep()
 
 			// This is safe even if args[1] contains unknowns because the HCL
 			// template renderer itself knows how to short-circuit those.
-			val, err := renderTmpl(expr, args[1])
+			val, err := renderTmpl(expr, vars)
 			return val.Type(), err
 		},
 		Impl: func(args []cty.Value, retType cty.Type) (cty.Value, error) {

internal/lang/funcs/filesystem_test.go

@@ -211,9 +211,9 @@ func TestTemplateFile(t *testing.T) {
 					cty.StringVal("a"),
 					cty.StringVal("b").Mark("var"),
 					cty.StringVal("c"),
-				}),
+				}).Mark("vars"),
 			}),
-			cty.StringVal("- a\n- b\n- c\n").Mark("path").Mark("var"),
+			cty.StringVal("- a\n- b\n- c\n").Mark("path").Mark("var").Mark("vars"),
 			``,
 		},
 		{