gh-158876: Update bundled Expat to 2.9.0

Makefile.pre.in

@@ -618,6 +618,7 @@ DTRACE_DEPS = \
 # pyexpat's expat library
 
 LIBEXPAT_OBJS= \
+		Modules/expat/xcs.o \
 		Modules/expat/xmlparse.o \
 		Modules/expat/xmlrole.o \
 		Modules/expat/xmltok.o
@@ -638,7 +639,7 @@ LIBEXPAT_HEADERS= \
 		Modules/expat/pyexpatns.h \
 		Modules/expat/siphash.h \
 		Modules/expat/utf8tab.h \
-		Modules/expat/xcsinc.c \
+		Modules/expat/xcs.h \
 		Modules/expat/xmlrole.h \
 		Modules/expat/xmltok.h \
 		Modules/expat/xmltok_impl.h \
@@ -1450,6 +1451,9 @@ PYTHON_HEADERS= \
 # Build static libexpat.a
 LIBEXPAT_CFLAGS=@LIBEXPAT_CFLAGS@ $(PY_STDMODULE_CFLAGS) $(CCSHARED)
 
+Modules/expat/xcs.o: $(srcdir)/Modules/expat/xcs.c $(LIBEXPAT_HEADERS) $(PYTHON_HEADERS)
+	$(CC) -c $(LIBEXPAT_CFLAGS) -o $@ $(srcdir)/Modules/expat/xcs.c
+
 Modules/expat/xmlparse.o: $(srcdir)/Modules/expat/xmlparse.c $(LIBEXPAT_HEADERS) $(PYTHON_HEADERS)
 	$(CC) -c $(LIBEXPAT_CFLAGS) -o $@ $(srcdir)/Modules/expat/xmlparse.c
 

Misc/NEWS.d/next/Security/2026-08-31-16-47-33.gh-issue-157953.KxCF5N.rst

@@ -1 +1 @@
-Update bundled `libexpat <https://libexpat.github.io/>`_ to version 2.8.5.
+Update bundled `libexpat <https://libexpat.github.io/>`_ to version 2.9.0.

Modules/expat/expat.h

@@ -48,7 +48,7 @@
 #ifndef Expat_INCLUDED
 #  define Expat_INCLUDED 1
 
-#  include <stdint.h> // for uint8_t
+#  include <stdint.h> // for int64_t, uint8_t, uint64_t
 #  include <stdlib.h>
 #  include "expat_external.h"
 
@@ -140,6 +140,26 @@ enum XML_Error {
   XML_ERROR_NOT_STARTED,
 };
 
+/* Added in 2.9.0. */
+enum XML_Prop_Error {
+  XML_PROP_ERROR_NONE = 0, // i.e. success
+
+  XML_PROP_ERROR_INVALID_KEY = 1,   // i.e. the property is not known at all
+  XML_PROP_ERROR_INVALID_TYPE = 2,  // i.e. the property is known but expects a
+                                    // different type (so a different
+                                    // getter/setter would need to be called)
+  XML_PROP_ERROR_INVALID_VALUE = 3, // i.e. the value is invalid (with a setter
+                                    // function) or a NULL-pointer (with a
+                                    // getter function)
+
+  XML_PROP_ERROR_PARSER_NULL = 4,     // i.e. the parser argument is NULL
+  XML_PROP_ERROR_PARSER_NOT_ROOT = 5, // i.e. the parser is not a root parser
+                                      // but a subparser (and a root parser is
+                                      // needed)
+
+  /* potentially more error codes upcoming here */
+};
+
 enum XML_Content_Type {
   XML_CTYPE_EMPTY = 1,
   XML_CTYPE_ANY,
@@ -757,29 +777,6 @@ XML_GetSpecifiedAttributeCount(XML_Parser parser);
 XMLPARSEAPI(int)
 XML_GetIdAttributeIndex(XML_Parser parser);
 
-#  ifdef XML_ATTR_INFO
-/* Source file byte offsets for the start and end of attribute names and values.
-   The value indices are exclusive of surrounding quotes; thus in a UTF-8 source
-   file an attribute value of "blah" will yield:
-   info->valueEnd - info->valueStart = 4 bytes.
-*/
-typedef struct {
-  XML_Index nameStart;  /* Offset to beginning of the attribute name. */
-  XML_Index nameEnd;    /* Offset after the attribute name's last byte. */
-  XML_Index valueStart; /* Offset to beginning of the attribute value. */
-  XML_Index valueEnd;   /* Offset after the attribute value's last byte. */
-} XML_AttrInfo;
-
-/* Returns an array of XML_AttrInfo structures for the attribute/value pairs
-   passed in last call to the XML_StartElementHandler that were specified
-   in the start-tag rather than defaulted. Each attribute/value pair counts
-   as 1; thus the number of entries in the array is
-   XML_GetSpecifiedAttributeCount(parser) / 2.
-*/
-XMLPARSEAPI(const XML_AttrInfo *)
-XML_GetAttributeInfo(XML_Parser parser);
-#  endif
-
 /* Parses some input. Returns XML_STATUS_ERROR if a fatal error is
    detected.  The last call to XML_Parse must have isFinal true; len
    may be zero for this call (or any other).
@@ -964,15 +961,24 @@ XML_GetErrorCode(XML_Parser parser);
    return 0 to indicate an error.
    Note: XML_GetCurrentByteIndex returns -1 to indicate an error.
 */
+XML_ATTR_DEPRECATED("please use XML_GetCurrentLineNumber64 instead")
 XMLPARSEAPI(XML_Size) XML_GetCurrentLineNumber(XML_Parser parser);
+XMLPARSEAPI(uint64_t) XML_GetCurrentLineNumber64(XML_Parser parser);
+XML_ATTR_DEPRECATED("please use XML_GetCurrentColumnNumber64 instead")
 XMLPARSEAPI(XML_Size) XML_GetCurrentColumnNumber(XML_Parser parser);
+XMLPARSEAPI(uint64_t) XML_GetCurrentColumnNumber64(XML_Parser parser);
+XML_ATTR_DEPRECATED("please use XML_GetCurrentByteIndex64 instead")
 XMLPARSEAPI(XML_Index) XML_GetCurrentByteIndex(XML_Parser parser);
+XMLPARSEAPI(int64_t) XML_GetCurrentByteIndex64(XML_Parser parser);
 
 /* Return the number of bytes in the current event.
    Returns 0 if the event is in an internal entity.
 */
+XML_ATTR_DEPRECATED("please use XML_GetCurrentByteCount64 instead")
 XMLPARSEAPI(int)
 XML_GetCurrentByteCount(XML_Parser parser);
+XMLPARSEAPI(uint64_t)
+XML_GetCurrentByteCount64(XML_Parser parser);
 
 /* If XML_CONTEXT_BYTES is >=1, returns the input buffer, sets
    the integer pointed to by offset to the offset within this buffer
@@ -984,8 +990,11 @@ XML_GetCurrentByteCount(XML_Parser parser);
    NOTE: The character pointer returned should not be used outside
    the handler that makes the call.
 */
+XML_ATTR_DEPRECATED("please use XML_GetInputContext64 instead")
 XMLPARSEAPI(const char *)
 XML_GetInputContext(XML_Parser parser, int *offset, int *size);
+XMLPARSEAPI(const char *)
+XML_GetInputContext64(XML_Parser parser, int64_t *offset, uint64_t *size);
 
 /* For backwards compatibility with previous versions. */
 #  define XML_GetErrorLineNumber XML_GetCurrentLineNumber
@@ -1040,14 +1049,15 @@ enum XML_FeatureEnum {
   XML_FEATURE_UNICODE_WCHAR_T,
   XML_FEATURE_DTD,
   XML_FEATURE_CONTEXT_BYTES,
+  /* Added in Expat 1.95.5, removed in Expat 2.9.0. */
   XML_FEATURE_MIN_SIZE,
   XML_FEATURE_SIZEOF_XML_CHAR,
   XML_FEATURE_SIZEOF_XML_LCHAR,
   /* Added in Expat 2.0.0. */
   XML_FEATURE_NS,
   /* Added in Expat 2.0.1. */
   XML_FEATURE_LARGE_SIZE,
-  /* Added in Expat 2.1.0. */
+  /* Added in Expat 2.1.0, removed in Expat 2.9.0. */
   XML_FEATURE_ATTR_INFO,
   /* Added in Expat 2.4.0. */
   XML_FEATURE_BILLION_LAUGHS_ATTACK_PROTECTION_MAXIMUM_AMPLIFICATION_DEFAULT,
@@ -1069,6 +1079,41 @@ typedef struct {
 XMLPARSEAPI(const XML_Feature *)
 XML_GetFeatureList(void);
 
+/* Added in Expat 2.9.0. */
+enum XML_Parser_Property {
+#  if defined(XML_TESTING)
+  XML_PROP_INVALID = 0,
+#  endif
+#  if XML_GE == 1
+  XML_PROP_ALLOC_TRACKER_ACTIVATION_THRESHOLD = 1,   // of type `uint64_t`
+  XML_PROP_ALLOC_TRACKER_MAXIMUM_AMPLIFICATION = 2,  // of type `double`
+  XML_PROP_BILLION_LAUGHS_ACTIVATION_THRESHOLD = 3,  // of type `uint64_t`
+  XML_PROP_BILLION_LAUGHS_MAXIMUM_AMPLIFICATION = 4, // of type `double`
+#  endif
+  XML_PROP_REPARSE_DEFERRAL_ENABLED = 5, // of type `XML_Bool`
+  /* more properties upcoming here */
+};
+
+/* Added in Expat 2.9.0. */
+XMLPARSEAPI(enum XML_Prop_Error)
+XML_GetPropertyBool(XML_Parser parser, enum XML_Parser_Property property,
+                    XML_Bool *value);
+XMLPARSEAPI(enum XML_Prop_Error)
+XML_GetPropertyDouble(XML_Parser parser, enum XML_Parser_Property property,
+                      double *value);
+XMLPARSEAPI(enum XML_Prop_Error)
+XML_GetPropertyUInt64(XML_Parser parser, enum XML_Parser_Property property,
+                      uint64_t *value);
+XMLPARSEAPI(enum XML_Prop_Error)
+XML_SetPropertyBool(XML_Parser parser, enum XML_Parser_Property property,
+                    XML_Bool value);
+XMLPARSEAPI(enum XML_Prop_Error)
+XML_SetPropertyDouble(XML_Parser parser, enum XML_Parser_Property property,
+                      double value);
+XMLPARSEAPI(enum XML_Prop_Error)
+XML_SetPropertyUInt64(XML_Parser parser, enum XML_Parser_Property property,
+                      uint64_t value);
+
 #  if defined(XML_DTD) || (defined(XML_GE) && XML_GE == 1)
 /* Added in Expat 2.4.0 for XML_DTD defined and
  * added in Expat 2.6.0 for XML_GE == 1. */
@@ -1101,8 +1146,8 @@ XML_SetReparseDeferralEnabled(XML_Parser parser, XML_Bool enabled);
    See https://semver.org
 */
 #  define XML_MAJOR_VERSION 2
-#  define XML_MINOR_VERSION 8
-#  define XML_MICRO_VERSION 5
+#  define XML_MINOR_VERSION 9
+#  define XML_MICRO_VERSION 0
 
 #  ifdef __cplusplus
 }

Modules/expat/expat_external.h

@@ -169,6 +169,9 @@ typedef char XML_LChar;
 #  endif   /* XML_UNICODE */
 
 #  ifdef XML_LARGE_SIZE /* Use large integers for file/stream positions. */
+#    if defined(__clang__) || defined(__GNUC__)
+#      warning Macro XML_LARGE_SIZE is deprecated, please use the 64bit location API functions instead.
+#    endif
 typedef long long XML_Index;
 typedef unsigned long long XML_Size;
 #  else

Modules/expat/internal.h

@@ -56,13 +56,11 @@
 #if ! defined(INTERNAL_H)
 #  define INTERNAL_H 1
 
-#  ifndef XML_MIN_SIZE
-#    if ! defined(inline)
-#      ifdef __GNUC__
-#        define inline __inline
-#      endif /* __GNUC__ */
-#    endif
-#  endif /* XML_MIN_SIZE */
+#  if ! defined(inline)
+#    ifdef __GNUC__
+#      define inline __inline
+#    endif /* __GNUC__ */
+#  endif
 
 #  ifndef inline
 #    define inline