only unmark deep once for ValidateDeep

internal/deprecation/deprecation.go

@@ -50,8 +50,7 @@ func (d *Deprecations) Validate(value cty.Value, module addrs.Module, rng *hcl.R
 
 // ValidateDeep does the same as Validate but checks deeply nested deprecation marks as well.
 func (d *Deprecations) ValidateDeep(value cty.Value, module addrs.Module, rng *hcl.Range) (cty.Value, tfdiags.Diagnostics) {
-	deprecationMarks := marks.GetDeprecationMarksDeep(value)
+	notDeprecatedValue, deprecationMarks := marks.GetDeprecationMarksDeep(value)
-	notDeprecatedValue := marks.RemoveDeprecationMarksDeep(value)
 	return notDeprecatedValue, d.deprecationMarksToDiagnostics(deprecationMarks, module, rng)
 }
 

internal/lang/marks/marks.go

@@ -70,9 +70,9 @@ func GetDeprecationMarks(val cty.Value) []DeprecationMark {
 
 // GetDeprecationMarksDeep returns all deprecation marks present on the given
 // cty.Value or any nested values.
-func GetDeprecationMarksDeep(val cty.Value) []DeprecationMark {
+func GetDeprecationMarksDeep(val cty.Value) (cty.Value, []DeprecationMark) {
-	_, marks := val.UnmarkDeep()
+	unmarked, marks := val.UnmarkDeep()
-	return FilterDeprecationMarks(marks)
+	return unmarked, FilterDeprecationMarks(marks)
 }
 
 // RemoveDeprecationMarks returns a copy of the given cty.Value with all