tests: Protect against nested element declaration model regressions

1 files changed, 77 insertions, 0 deletions

diff --git a/expat/tests/runtests.c b/expat/tests/runtests.c
index 2cd4acbe..e28670d2 100644
--- a/expat/tests/runtests.c
+++ b/expat/tests/runtests.c
@@ -2664,6 +2664,82 @@ START_TEST(test_dtd_elements) {
 }
 END_TEST
 
+static void XMLCALL
+element_decl_check_model(void *userData, const XML_Char *name,
+                         XML_Content *model) {
+  UNUSED_P(userData);
+  uint32_t errorFlags = 0;
+
+  /* Expected model array structure is this:
+   * [0] (type 6, quant 0)
+   *   [1] (type 5, quant 0)
+   *     [3] (type 4, quant 0, name "bar")
+   *     [4] (type 4, quant 0, name "foo")
+   *     [5] (type 4, quant 3, name "xyz")
+   *   [2] (type 4, quant 2, name "zebra")
+   */
+  errorFlags |= ((xcstrcmp(name, XCS("junk")) == 0) ? 0 : (1u << 0));
+  errorFlags |= ((model != NULL) ? 0 : (1u << 1));
+
+  errorFlags |= ((model[0].type == XML_CTYPE_SEQ) ? 0 : (1u << 2));
+  errorFlags |= ((model[0].quant == XML_CQUANT_NONE) ? 0 : (1u << 3));
+  errorFlags |= ((model[0].numchildren == 2) ? 0 : (1u << 4));
+  errorFlags |= ((model[0].children == &model[1]) ? 0 : (1u << 5));
+  errorFlags |= ((model[0].name == NULL) ? 0 : (1u << 6));
+
+  errorFlags |= ((model[1].type == XML_CTYPE_CHOICE) ? 0 : (1u << 7));
+  errorFlags |= ((model[1].quant == XML_CQUANT_NONE) ? 0 : (1u << 8));
+  errorFlags |= ((model[1].numchildren == 3) ? 0 : (1u << 9));
+  errorFlags |= ((model[1].children == &model[3]) ? 0 : (1u << 10));
+  errorFlags |= ((model[1].name == NULL) ? 0 : (1u << 11));
+
+  errorFlags |= ((model[2].type == XML_CTYPE_NAME) ? 0 : (1u << 12));
+  errorFlags |= ((model[2].quant == XML_CQUANT_REP) ? 0 : (1u << 13));
+  errorFlags |= ((model[2].numchildren == 0) ? 0 : (1u << 14));
+  errorFlags |= ((model[2].children == NULL) ? 0 : (1u << 15));
+  errorFlags |= ((xcstrcmp(model[2].name, XCS("zebra")) == 0) ? 0 : (1u << 16));
+
+  errorFlags |= ((model[3].type == XML_CTYPE_NAME) ? 0 : (1u << 17));
+  errorFlags |= ((model[3].quant == XML_CQUANT_NONE) ? 0 : (1u << 18));
+  errorFlags |= ((model[3].numchildren == 0) ? 0 : (1u << 19));
+  errorFlags |= ((model[3].children == NULL) ? 0 : (1u << 20));
+  errorFlags |= ((xcstrcmp(model[3].name, XCS("bar")) == 0) ? 0 : (1u << 21));
+
+  errorFlags |= ((model[4].type == XML_CTYPE_NAME) ? 0 : (1u << 22));
+  errorFlags |= ((model[4].quant == XML_CQUANT_NONE) ? 0 : (1u << 23));
+  errorFlags |= ((model[4].numchildren == 0) ? 0 : (1u << 24));
+  errorFlags |= ((model[4].children == NULL) ? 0 : (1u << 25));
+  errorFlags |= ((xcstrcmp(model[4].name, XCS("foo")) == 0) ? 0 : (1u << 26));
+
+  errorFlags |= ((model[5].type == XML_CTYPE_NAME) ? 0 : (1u << 27));
+  errorFlags |= ((model[5].quant == XML_CQUANT_PLUS) ? 0 : (1u << 28));
+  errorFlags |= ((model[5].numchildren == 0) ? 0 : (1u << 29));
+  errorFlags |= ((model[5].children == NULL) ? 0 : (1u << 30));
+  errorFlags |= ((xcstrcmp(model[5].name, XCS("xyz")) == 0) ? 0 : (1u << 31));
+
+  XML_SetUserData(g_parser, (void *)(uintptr_t)errorFlags);
+  XML_FreeContentModel(g_parser, model);
+}
+
+START_TEST(test_dtd_elements_nesting) {
+  // Payload inspired by a test in Perl's XML::Parser
+  const char *text = "<!DOCTYPE foo [\n"
+                     "<!ELEMENT junk ((bar|foo|xyz+), zebra*)>\n"
+                     "]>\n"
+                     "<foo/>";
+
+  XML_SetUserData(g_parser, (void *)(uintptr_t)-1);
+
+  XML_SetElementDeclHandler(g_parser, element_decl_check_model);
+  if (XML_Parse(g_parser, text, (int)strlen(text), XML_TRUE)
+      == XML_STATUS_ERROR)
+    xml_failure(g_parser);
+
+  if ((uint32_t)(uintptr_t)XML_GetUserData(g_parser) != 0)
+    fail("Element declaration model regression detected");
+}
+END_TEST
+
 /* Test foreign DTD handling */
 START_TEST(test_set_foreign_dtd) {
   const char *text1 = "<?xml version='1.0' encoding='us-ascii'?>\n";
@@ -11863,6 +11939,7 @@ make_suite(void) {
   tcase_add_test(tc_basic, test_memory_allocation);
   tcase_add_test(tc_basic, test_default_current);
   tcase_add_test(tc_basic, test_dtd_elements);
+  tcase_add_test(tc_basic, test_dtd_elements_nesting);
   tcase_add_test__ifdef_xml_dtd(tc_basic, test_set_foreign_dtd);
   tcase_add_test__ifdef_xml_dtd(tc_basic, test_foreign_dtd_not_standalone);
   tcase_add_test__ifdef_xml_dtd(tc_basic, test_invalid_foreign_dtd);