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author | Noah Misch <noah@leadboat.com> | 2017-11-11 11:10:53 -0800 |
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committer | Noah Misch <noah@leadboat.com> | 2017-11-11 11:11:21 -0800 |
commit | e7083dfce5754e38063502c683b7b7fa57021893 (patch) | |
tree | b47df0cdb68a1678af339ea3f6ab4e87621cb716 /src/backend/utils/adt/xml.c | |
parent | 9efd83bfd32b38c675b263f532ebe9a6ec53149e (diff) | |
download | postgresql-e7083dfce5754e38063502c683b7b7fa57021893.tar.gz postgresql-e7083dfce5754e38063502c683b7b7fa57021893.zip |
Ignore XML declaration in xpath_internal(), for UTF8 databases.
When a value contained an XML declaration naming some other encoding,
this function interpreted UTF8 bytes as the named encoding, yielding
mojibake. xml_parse() already has similar logic. This would be
necessary but not sufficient for non-UTF8 databases, so preserve
behavior there until the xpath facility can support such databases
comprehensively. Back-patch to 9.3 (all supported versions).
Pavel Stehule and Noah Misch
Discussion: https://postgr.es/m/CAFj8pRC-dM=tT=QkGi+Achkm+gwPmjyOayGuUfXVumCxkDgYWg@mail.gmail.com
Diffstat (limited to 'src/backend/utils/adt/xml.c')
-rw-r--r-- | src/backend/utils/adt/xml.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/src/backend/utils/adt/xml.c b/src/backend/utils/adt/xml.c index 268d577b94b..96f187c6ef4 100644 --- a/src/backend/utils/adt/xml.c +++ b/src/backend/utils/adt/xml.c @@ -3780,6 +3780,7 @@ xpath_internal(text *xpath_expr_text, xmltype *data, ArrayType *namespaces, int32 xpath_len; xmlChar *string; xmlChar *xpath_expr; + size_t xmldecl_len = 0; int i; int ndim; Datum *ns_names_uris; @@ -3840,6 +3841,16 @@ xpath_internal(text *xpath_expr_text, xmltype *data, ArrayType *namespaces, memcpy(xpath_expr, VARDATA(xpath_expr_text), xpath_len); xpath_expr[xpath_len] = '\0'; + /* + * In a UTF8 database, skip any xml declaration, which might assert + * another encoding. Ignore parse_xml_decl() failure, letting + * xmlCtxtReadMemory() report parse errors. Documentation disclaims + * xpath() support for non-ASCII data in non-UTF8 databases, so leave + * those scenarios bug-compatible with historical behavior. + */ + if (GetDatabaseEncoding() == PG_UTF8) + parse_xml_decl(string, &xmldecl_len, NULL, NULL, NULL); + xmlerrcxt = pg_xml_init(PG_XML_STRICTNESS_ALL); PG_TRY(); @@ -3854,7 +3865,8 @@ xpath_internal(text *xpath_expr_text, xmltype *data, ArrayType *namespaces, if (ctxt == NULL || xmlerrcxt->err_occurred) xml_ereport(xmlerrcxt, ERROR, ERRCODE_OUT_OF_MEMORY, "could not allocate parser context"); - doc = xmlCtxtReadMemory(ctxt, (char *) string, len, NULL, NULL, 0); + doc = xmlCtxtReadMemory(ctxt, (char *) string + xmldecl_len, + len - xmldecl_len, NULL, NULL, 0); if (doc == NULL || xmlerrcxt->err_occurred) xml_ereport(xmlerrcxt, ERROR, ERRCODE_INVALID_XML_DOCUMENT, "could not parse XML document"); |