bpo-30947: Update libexpat from 2.2.1 to 2.2.3 (#3106)
* bpo-30947: Update libexpat from 2.2.1 to 2.2.3
* Add NEWS entry
* Add new loadlibrary.c
* expat_external.h: restore include "pyexpatns.h"
* PCbuild: add expat/loadlibrary.c
* Define XML_POOR_ENTROPY to compile expat
diff --git a/Modules/expat/xmlrole.c b/Modules/expat/xmlrole.c
index a7c5630..c809ee5 100644
--- a/Modules/expat/xmlrole.c
+++ b/Modules/expat/xmlrole.c
@@ -170,7 +170,14 @@
case XML_TOK_COMMENT:
return XML_ROLE_COMMENT;
case XML_TOK_BOM:
- return XML_ROLE_NONE;
+ /* This case can never arise. To reach this role function, the
+ * parse must have passed through prolog0 and therefore have had
+ * some form of input, even if only a space. At that point, a
+ * byte order mark is no longer a valid character (though
+ * technically it should be interpreted as a non-breaking space),
+ * so will be rejected by the tokenizing stages.
+ */
+ return XML_ROLE_NONE; /* LCOV_EXCL_LINE */
case XML_TOK_DECL_OPEN:
if (!XmlNameMatchesAscii(enc,
ptr + 2 * MIN_BYTES_PER_CHAR(enc),
@@ -1285,6 +1292,26 @@
return common(state, tok);
}
+/* This function will only be invoked if the internal logic of the
+ * parser has broken down. It is used in two cases:
+ *
+ * 1: When the XML prolog has been finished. At this point the
+ * processor (the parser level above these role handlers) should
+ * switch from prologProcessor to contentProcessor and reinitialise
+ * the handler function.
+ *
+ * 2: When an error has been detected (via common() below). At this
+ * point again the processor should be switched to errorProcessor,
+ * which will never call a handler.
+ *
+ * The result of this is that error() can only be called if the
+ * processor switch failed to happen, which is an internal error and
+ * therefore we shouldn't be able to provoke it simply by using the
+ * library. It is a necessary backstop, however, so we merely exclude
+ * it from the coverage statistics.
+ *
+ * LCOV_EXCL_START
+ */
static int PTRCALL
error(PROLOG_STATE *UNUSED_P(state),
int UNUSED_P(tok),
@@ -1294,6 +1321,7 @@
{
return XML_ROLE_NONE;
}
+/* LCOV_EXCL_STOP */
static int FASTCALL
common(PROLOG_STATE *state, int tok)