fix(gnovm): map key deletion in realms (#2017)

<!-- please provide a detailed description of the changes made in this
pull request. -->

after value is delete in map by `delete(map, key)`, map variable wasn't
updating it-self

<details><summary>Contributors' checklist...</summary>

- [x] Added new tests, or not needed, or not feasible
- [ ] Provided an example (e.g. screenshot) to aid review or the PR is
self-explanatory
- [X] Updated the official documentation or not needed
- [x] No breaking changes were made, or a `BREAKING CHANGE: xxx` message
was included in the description
- [ ] Added references to related issues and PRs
- [ ] Provided any useful hints for running manual tests
- [ ] Added new benchmarks to [generated
graphs](https://gnoland.github.io/benchmarks), if any. More info
[here](https://github.com/gnolang/gno/blob/master/.benchmarks/README.md).
</details>

examples/gno.land/r/x/map_delete/map_delete.gno

@@ -0,0 +1,18 @@
+package mapdelete
+
+var mapus map[uint64]string = make(map[uint64]string)
+
+func init() {
+	mapus[3] = "three"
+	mapus[5] = "five"
+	mapus[9] = "nine"
+}
+
+func DeleteMap(k uint64) {
+	delete(mapus, k)
+}
+
+func GetMap(k uint64) bool {
+	_, exist := mapus[k]
+	return exist
+}

examples/gno.land/r/x/map_delete/map_delete_test.gno

@@ -0,0 +1,21 @@
+package mapdelete
+
+import (
+	"testing"
+)
+
+func TestGetMap(t *testing.T) {
+	if !(GetMap(3)) {
+		t.Error("Expected true, got ", GetMap(3))
+	}
+}
+
+func TestDeleteMap(t *testing.T) {
+	DeleteMap(3)
+}
+
+func TestGetMapAfterDelete(t *testing.T) {
+	if GetMap(3) {
+		t.Error("Expected false, got ", GetMap(3))
+	}
+}

gno.land/cmd/gnoland/testdata/map-delete.txtar

@@ -0,0 +1,41 @@
+gnoland start
+
+# add contract
+gnokey maketx addpkg -pkgdir $WORK -pkgpath gno.land/r/demo/mapdelete -gas-fee 1000000ugnot -gas-wanted 2000000 -broadcast -chainid=tendermint_test test1
+stdout OK!
+
+# delete map
+gnokey maketx call -pkgpath gno.land/r/demo/mapdelete -func DeleteMap -args 3 -gas-fee 1000000ugnot -gas-wanted 2000000 -broadcast -chainid=tendermint_test test1
+stdout OK!
+
+# check deletion
+gnokey maketx call -pkgpath gno.land/r/demo/mapdelete -func GetMap -args 3 -gas-fee 1000000ugnot -gas-wanted 2000000 -broadcast -chainid=tendermint_test test1
+stdout OK!
+stdout 'false bool'
+# XXX without patching uverse.go, expected stdout is
+# stdout 'true bool'
+
+
+
+-- gno.mod --
+module gno.land/r/demo/mapdelete
+
+-- realm.gno --
+package mapdelete
+
+var mapus map[uint64]string = make(map[uint64]string)
+
+func init() {
+	mapus[3] = "three"
+	mapus[5] = "five"
+	mapus[9] = "nine"
+}
+
+func DeleteMap(k uint64) {
+	delete(mapus, k)
+}
+
+func GetMap(k uint64) bool {
+	_, exist := mapus[k]
+	return exist
+}

gnovm/pkg/gnolang/uverse.go

@@ -709,7 +709,24 @@ func UverseNode() *PackageNode {
 			switch cbt := baseOf(arg0.TV.T).(type) {
 			case *MapType:
 				mv := arg0.TV.V.(*MapValue)
+				val, ok := mv.GetValueForKey(m.Store, &itv)
+				if !ok {
+					return
+				}
+
+				// delete
 				mv.DeleteForKey(m.Store, &itv)
+
+				if m.Realm != nil {
+					// mark key as deleted
+					keyObj := itv.GetFirstObject(m.Store)
+					m.Realm.DidUpdate(mv, keyObj, nil)
+
+					// mark value as deleted
+					valObj := val.GetFirstObject(m.Store)
+					m.Realm.DidUpdate(mv, valObj, nil)
+				}
+
 				return
 			case *NativeType:
 				krv := reflect.New(cbt.Type.Key()).Elem()