tpl/collections: Some more params merge adjustments

* If the end result is maps.Params, we need to lower the keys
* Also make sure to handle nested maps of different type

Update #6633

tpl/collections/merge.go

@@ -17,6 +17,8 @@ import (
  "reflect"
  "strings"
 
+ "github.com/gohugoio/hugo/common/maps"
+
  "github.com/gohugoio/hugo/common/hreflect"
 
  "github.com/pkg/errors"
@@ -68,6 +70,9 @@ func mergeMap(dst, src reflect.Value) reflect.Value {
 
  out := reflect.MakeMap(dst.Type())
 
+ // If the destination is Params, we must lower case all keys.
+ _, lowerCase := dst.Interface().(maps.Params)
+
  // Copy the destination map.
  for _, key := range dst.MapKeys() {
  v := dst.MapIndex(key)
@@ -81,15 +86,18 @@ func mergeMap(dst, src reflect.Value) reflect.Value {
  dv, found := caseInsensitiveLookup(dst, key)
 
  if found {
- // If both are the same map type, merge.
+ // If both are the same map key type, merge.
  dve := dv.Elem()
  if dve.Kind() == reflect.Map {
  sve := sv.Elem()
- if dve.Type() == sve.Type() {
+ if dve.Type().Key() == sve.Type().Key() {
  out.SetMapIndex(key, mergeMap(dve, sve))
  }
  }
  } else {
+ if lowerCase && key.Kind() == reflect.String {
+ key = reflect.ValueOf(strings.ToLower(key.String()))
+ }
  out.SetMapIndex(key, sv)
  }
  }

tpl/collections/merge_test.go

@@ -66,11 +66,25 @@ func TestMerge(t *testing.T) {
  map[string]interface{}{"a": 42, "c": 3},
  maps.Params{"a": int(1), "b": int(2), "c": int(3)}, false},
  {
- // https://github.com/gohugoio/hugo/issues/6633
+ "params dst, upper case src",
+ maps.Params{"a": 1, "b": 2},
+ map[string]interface{}{"a": 42, "C": 3},
+ maps.Params{"a": int(1), "b": int(2), "c": int(3)}, false},
+ {
  "params src",
  map[string]interface{}{"a": 1, "c": 2},
  maps.Params{"a": 42, "c": 3},
  map[string]interface{}{"a": int(1), "c": int(2)}, false},
+ {
+ "params src, upper case dst",
+ map[string]interface{}{"a": 1, "C": 2},
+ maps.Params{"a": 42, "c": 3},
+ map[string]interface{}{"a": int(1), "C": int(2)}, false},
+ {
+ "nested, params dst",
+ maps.Params{"a": 1, "b": maps.Params{"d": 1, "e": 2}},
+ map[string]interface{}{"a": 42, "c": 3, "b": map[string]interface{}{"d": 55, "e": 66, "f": 3}},
+ maps.Params{"a": 1, "b": maps.Params{"d": 1, "e": 2, "f": 3}, "c": 3}, false},
  {"src nil", simpleMap, nil, simpleMap, false},
  // Error cases.
  {"dst not a map", "not a map", nil, nil, true},