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| author | Noah Misch <noah@leadboat.com> | 2017-11-11 11:10:53 -0800 |
|---|---|---|
| committer | Noah Misch <noah@leadboat.com> | 2017-11-11 11:10:53 -0800 |
| commit | 2918fcedbf2b2adab688a7849ecce4556ef912ac (patch) | |
| tree | 9dbd6aa811f50aedac8a4a637cdcca162d50cee4 /src/backend/utils/adt/xml.c | |
| parent | 5edc63bda68a77c4d38f0cbeae1c4271f9ef4100 (diff) | |
| download | postgresql-2918fcedbf2b2adab688a7849ecce4556ef912ac.tar.gz | |
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 56e262819e..fa392cd0e5 100644 --- a/src/backend/utils/adt/xml.c +++ b/src/backend/utils/adt/xml.c @@ -3845,6 +3845,7 @@ 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; @@ -3900,6 +3901,16 @@ xpath_internal(text *xpath_expr_text, xmltype *data, ArrayType *namespaces, string = pg_xmlCharStrndup(datastr, len); xpath_expr = pg_xmlCharStrndup(VARDATA_ANY(xpath_expr_text), xpath_len); + /* + * 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(); @@ -3914,7 +3925,8 @@ 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"); |