Merge pull request #49107 from timothyqiu/circular-structure

Fix json dump and print of circular structure

3 files changed, 19 insertions, 6 deletions

diff --git a/core/io/json.cpp b/core/io/json.cpp
index e3e9d6158b..82ef2a6894 100644
--- a/core/io/json.cpp
+++ b/core/io/json.cpp
@@ -55,7 +55,7 @@ static String _make_indent(const String &p_indent, int p_size) {
 	return indent_text;
 }
 
-String JSON::_print_var(const Variant &p_var, const String &p_indent, int p_cur_indent, bool p_sort_keys, bool p_full_precision) {
+String JSON::_print_var(const Variant &p_var, const String &p_indent, int p_cur_indent, bool p_sort_keys, Set<const void *> &p_markers, bool p_full_precision) {
 	String colon = ":";
 	String end_statement = "";
 
@@ -91,20 +91,29 @@ String JSON::_print_var(const Variant &p_var, const String &p_indent, int p_cur_
 			String s = "[";
 			s += end_statement;
 			Array a = p_var;
+
+			ERR_FAIL_COND_V_MSG(p_markers.has(a.id()), "\"[...]\"", "Converting circular structure to JSON.");
+			p_markers.insert(a.id());
+
 			for (int i = 0; i < a.size(); i++) {
 				if (i > 0) {
 					s += ",";
 					s += end_statement;
 				}
-				s += _make_indent(p_indent, p_cur_indent + 1) + _print_var(a[i], p_indent, p_cur_indent + 1, p_sort_keys);
+				s += _make_indent(p_indent, p_cur_indent + 1) + _print_var(a[i], p_indent, p_cur_indent + 1, p_sort_keys, p_markers);
 			}
 			s += end_statement + _make_indent(p_indent, p_cur_indent) + "]";
+			p_markers.erase(a.id());
 			return s;
 		}
 		case Variant::DICTIONARY: {
 			String s = "{";
 			s += end_statement;
 			Dictionary d = p_var;
+
+			ERR_FAIL_COND_V_MSG(p_markers.has(d.id()), "\"{...}\"", "Converting circular structure to JSON.");
+			p_markers.insert(d.id());
+
 			List<Variant> keys;
 			d.get_key_list(&keys);
 
@@ -117,12 +126,13 @@ String JSON::_print_var(const Variant &p_var, const String &p_indent, int p_cur_
 					s += ",";
 					s += end_statement;
 				}
-				s += _make_indent(p_indent, p_cur_indent + 1) + _print_var(String(E->get()), p_indent, p_cur_indent + 1, p_sort_keys);
+				s += _make_indent(p_indent, p_cur_indent + 1) + _print_var(String(E->get()), p_indent, p_cur_indent + 1, p_sort_keys, p_markers);
 				s += colon;
-				s += _print_var(d[E->get()], p_indent, p_cur_indent + 1, p_sort_keys);
+				s += _print_var(d[E->get()], p_indent, p_cur_indent + 1, p_sort_keys, p_markers);
 			}
 
 			s += end_statement + _make_indent(p_indent, p_cur_indent) + "}";
+			p_markers.erase(d.id());
 			return s;
 		}
 		default:
@@ -131,7 +141,8 @@ String JSON::_print_var(const Variant &p_var, const String &p_indent, int p_cur_
 }
 
 String JSON::print(const Variant &p_var, const String &p_indent, bool p_sort_keys, bool p_full_precision) {
-	return _print_var(p_var, p_indent, 0, p_sort_keys, p_full_precision);
+	Set<const void *> markers;
+	return _print_var(p_var, p_indent, 0, p_sort_keys, markers, p_full_precision);
 }
 
 Error JSON::_get_token(const char32_t *p_str, int &index, int p_len, Token &r_token, int &line, String &r_err_str) {
diff --git a/core/io/json.h b/core/io/json.h
index bfd2347725..5be8cc1e86 100644
--- a/core/io/json.h
+++ b/core/io/json.h
@@ -62,7 +62,7 @@ class JSON {
 
 	static const char *tk_name[TK_MAX];
 
-	static String _print_var(const Variant &p_var, const String &p_indent, int p_cur_indent, bool p_sort_keys, bool p_full_precision = false);
+	static String _print_var(const Variant &p_var, const String &p_indent, int p_cur_indent, bool p_sort_keys, Set<const void *> &p_markers, bool p_full_precision = false);
 
 	static Error _get_token(const char32_t *p_str, int &index, int p_len, Token &r_token, int &line, String &r_err_str);
 	static Error _parse_value(Variant &value, Token &token, const char32_t *p_str, int &index, int p_len, int &line, String &r_err_str);
diff --git a/core/variant/variant.cpp b/core/variant/variant.cpp
index d10f41b833..4e45862fd3 100644
--- a/core/variant/variant.cpp
+++ b/core/variant/variant.cpp
@@ -1698,6 +1698,7 @@ String Variant::stringify(List<const void *> &stack) const {
 			}
 			str += "}";
 
+			stack.erase(d.id());
 			return str;
 		} break;
 		case PACKED_VECTOR2_ARRAY: {
@@ -1801,6 +1802,7 @@ String Variant::stringify(List<const void *> &stack) const {
 			}
 
 			str += "]";
+			stack.erase(arr.id());
 			return str;
 
 		} break;