parsing BUGFIX invalid backward extension parent pointer

This patch fixes the issue if extensions are used within subsequent
enum statements

Author: steweg

src/parser_yang.c

@@ -1937,9 +1937,17 @@ parse_type_enum(struct lysp_yang_ctx *ctx, enum ly_stmt enum_kw, struct lysp_typ
     size_t word_len;
     enum ly_stmt kw;
     struct lysp_type_enum *enm;
+    LY_ARRAY_COUNT_TYPE u, v;
 
     LY_ARRAY_NEW_RET(PARSER_CTX(ctx), *enums, enm, LY_EMEM);
 
+    /* revalidate the backward parent pointers from extensions */
+    LY_ARRAY_FOR(*enums, u) {
+        LY_ARRAY_FOR((*enums)[u].exts, v) {
+            (*enums)[u].exts[v].parent = &(*enums)[u];
+        }
+    }
+
     /* get value */
     LY_CHECK_RET(get_argument(ctx, enum_kw == LY_STMT_ENUM ? Y_STR_ARG : Y_IDENTIF_ARG, NULL, &word, &buf, &word_len));
     if (enum_kw == LY_STMT_ENUM) {

tests/utests/basic/test_plugins.c

@@ -31,6 +31,12 @@ const char *simple = "module libyang-plugins-simple {"
         "    type s:note {length 255;}"
         "    s:hint \"some hint here\";"
         "  }"
+        "  leaf enum1 {"
+        "    type enumeration {"
+        "      enum val1 {s:rt;}"
+        "      enum val2 {s:rt;}"
+        "    }"
+        "  }"
         "  grouping grp1 {"
         "    list l1 {key v; leaf v {type string;} leaf k {type string;}}"
         "    list l2 {key v; leaf v {type string;} leaf k {type string;}}"
@@ -132,6 +138,7 @@ parse_clb2(struct lysp_ctx *UNUSED(pctx), struct lysp_ext_instance *ext)
 {
     struct lysp_refine *refine;
     struct lysp_tpdf *tpdf;
+    struct lysp_type_enum *en;
     LY_ARRAY_COUNT_TYPE count = 0;
 
     if (ext->parent_stmt == LY_STMT_REFINE) {
@@ -140,6 +147,9 @@ parse_clb2(struct lysp_ctx *UNUSED(pctx), struct lysp_ext_instance *ext)
     } else if (ext->parent_stmt == LY_STMT_TYPEDEF) {
         tpdf = (struct lysp_tpdf *)ext->parent;
         count = LY_ARRAY_COUNT(tpdf->exts);
+    } else if (ext->parent_stmt == LY_STMT_ENUM) {
+        en = (struct lysp_type_enum *)ext->parent;
+        count = LY_ARRAY_COUNT(en->exts);
     } else {
         return LY_SUCCESS;
     }