Fix of printing of anydata with empty containers

This patch fixes JSON printing of empty containers within anydata node

src/parser_json.c

@@ -1085,6 +1085,7 @@ lydjson_parse_opaq(struct lyd_json_ctx *lydctx, const char *name, size_t name_le
     }
 
     if (*status_p == LYJSON_OBJECT) {
+        ((struct lyd_node_opaq *)*node_p)->hints |= LYD_NODEHINT_CONTAINER;
         /* process children */
         do {
             LY_CHECK_GOTO(ret = lydjson_subtree_r(lydctx, *node_p, lyd_node_child_p(*node_p), NULL), cleanup);

src/printer_json.c

@@ -582,7 +582,6 @@ json_print_any_content(struct jsonpr_ctx *pctx, struct lyd_node_any *any)
     if ((any->schema->nodetype == LYS_ANYDATA) && (any->value_type != LYD_ANYDATA_DATATREE)) {
         LOGINT_RET(pctx->ctx);
     }
-
     if (any->value_type == LYD_ANYDATA_LYB) {
         uint32_t parser_options = LYD_PARSE_ONLY | LYD_PARSE_OPAQ | LYD_PARSE_STRICT;
 
@@ -942,7 +941,7 @@ json_print_opaq(struct jsonpr_ctx *pctx, const struct lyd_node_opaq *node)
     } else if (node->hints & LYD_NODEHINT_LEAFLIST) {
         ly_print_(pctx->out, ",%s%*s", DO_FORMAT ? "\n" : "", INDENT);
     }
-    if (node->child || (node->hints & LYD_NODEHINT_LIST)) {
+    if (node->child || (node->hints & LYD_NODEHINT_LIST) || (node->hints & LYD_NODEHINT_CONTAINER)) {
         LY_CHECK_RET(json_print_inner(pctx, &node->node));
         LEVEL_PRINTED;
     } else {

src/tree_data.h

@@ -955,6 +955,7 @@ struct lyd_node_any {
  */
 #define LYD_NODEHINT_LIST       0x0080 /**< node is allowed to be a list instance */
 #define LYD_NODEHINT_LEAFLIST   0x0100 /**< node is allowed to be a leaf-list instance */
+#define LYD_NODEHINT_CONTAINER  0x0200 /**< node is allowed to be a container instance */
 /**
  * @} lydnodehints
  */
@@ -969,11 +970,11 @@ struct lyd_node_any {
  * Any information about value and node types encoded in the format is hinted by these values.
  * It combines [value hints](@ref lydvalhints) and [node hints](@ref lydnodehints).
  */
-#define LYD_HINT_DATA       0x01F3 /**< special node/value hint to be used for generic data node/value (for cases when
+#define LYD_HINT_DATA       0x03F3 /**< special node/value hint to be used for generic data node/value (for cases when
                                         there is no encoding or it does not provide any additional information about
                                         a node/value type); do not combine with specific [value hints](@ref lydvalhints)
                                         or [node hints](@ref lydnodehints). */
-#define LYD_HINT_SCHEMA     0x01FF /**< special node/value hint to be used for generic schema node/value(for cases when
+#define LYD_HINT_SCHEMA     0x03FF /**< special node/value hint to be used for generic schema node/value(for cases when
                                         there is no encoding or it does not provide any additional information about
                                         a node/value type); do not combine with specific [value hints](@ref lydvalhints)
                                         or [node hints](@ref lydnodehints). */

tests/utests/CMakeLists.txt

@@ -65,6 +65,7 @@ ly_add_utest(NAME tree_data_sorted SOURCES data/test_tree_data_sorted.c)
 ly_add_utest(NAME new SOURCES data/test_new.c)
 ly_add_utest(NAME parser_xml SOURCES data/test_parser_xml.c)
 ly_add_utest(NAME printer_xml SOURCES data/test_printer_xml.c)
+ly_add_utest(NAME printer_json SOURCES data/test_printer_json.c)
 ly_add_utest(NAME parser_json SOURCES data/test_parser_json.c)
 ly_add_utest(NAME lyb SOURCES data/test_lyb.c)
 ly_add_utest(NAME validation SOURCES data/test_validation.c)

tests/utests/data/test_printer_json.c

@@ -0,0 +1,51 @@
+/*
+ * @file test_printer_json.c
+ * @author: Radek Krejci <rkrejci@cesnet.cz>
+ * @brief unit tests for functions from printer_yang.c
+ *
+ * Copyright (c) 2019-2020 CESNET, z.s.p.o.
+ *
+ * This source code is licensed under BSD 3-Clause License (the "License").
+ * You may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://opensource.org/licenses/BSD-3-Clause
+ */
+#define _UTEST_MAIN_
+#include "utests.h"
+
+static int
+setup(void **state)
+{
+    const char *schema1 = "module schema1 {namespace urn:tests:schema1;prefix schema1;yang-version 1.1;"
+            "revision 2014-05-08;"
+            "anydata data;"
+            "}";
+
+    UTEST_SETUP;
+    UTEST_ADD_MODULE(schema1, LYS_IN_YANG, NULL, NULL);
+    return 0;
+}
+
+static void
+test_container_presence(void **state)
+{
+    struct lyd_node *tree;
+    char *buffer = NULL;
+    const char *data = "{\"schema1:data\":{\"cont1\":{}}}";
+
+    CHECK_PARSE_LYD_PARAM(data, LYD_JSON, 0, LYD_VALIDATE_PRESENT, LY_SUCCESS, tree);
+    assert_int_equal(LY_SUCCESS, lyd_print_mem(&buffer, tree, LYD_JSON, LYD_PRINT_SHRINK));
+    CHECK_STRING(buffer, data)
+    lyd_free_all(tree);
+}
+
+int
+main(void)
+{
+    const struct CMUnitTest tests[] = {
+        UTEST(test_container_presence, setup),
+    };
+
+    return cmocka_run_group_tests(tests, NULL, NULL);
+}