diff --git a/src/backend/utils/adt/xml.c b/src/backend/utils/adt/xml.c index 3884babc1b..4b9877ee0b 100644 --- a/src/backend/utils/adt/xml.c +++ b/src/backend/utils/adt/xml.c @@ -119,9 +119,10 @@ struct PgXmlErrorContext static xmlParserInputPtr xmlPgEntityLoader(const char *URL, const char *ID, xmlParserCtxtPtr ctxt); +static void xml_errsave(Node *escontext, PgXmlErrorContext *errcxt, + int sqlcode, const char *msg); static void xml_errorHandler(void *data, xmlErrorPtr error); -static void xml_ereport_by_code(int level, int sqlcode, - const char *msg, int code); +static int errdetail_for_xml_code(int code); static void chopStringInfoNewlines(StringInfo str); static void appendStringInfoLineSeparator(StringInfo str); @@ -143,7 +144,8 @@ static bool print_xml_decl(StringInfo buf, const xmlChar *version, pg_enc encoding, int standalone); static bool xml_doctype_in_content(const xmlChar *str); static xmlDocPtr xml_parse(text *data, XmlOptionType xmloption_arg, - bool preserve_whitespace, int encoding); + bool preserve_whitespace, int encoding, + Node *escontext); static text *xml_xmlnodetoxmltype(xmlNodePtr cur, PgXmlErrorContext *xmlerrcxt); static int xml_xpathobjtoxmlarray(xmlXPathObjectPtr xpathobj, ArrayBuildState *astate, @@ -261,14 +263,18 @@ xml_in(PG_FUNCTION_ARGS) xmltype *vardata; xmlDocPtr doc; + /* Build the result object. */ vardata = (xmltype *) cstring_to_text(s); /* - * Parse the data to check if it is well-formed XML data. Assume that - * ERROR occurred if parsing failed. + * Parse the data to check if it is well-formed XML data. + * + * Note: we don't need to worry about whether a soft error is detected. */ - doc = xml_parse(vardata, xmloption, true, GetDatabaseEncoding()); - xmlFreeDoc(doc); + doc = xml_parse(vardata, xmloption, true, GetDatabaseEncoding(), + fcinfo->context); + if (doc != NULL) + xmlFreeDoc(doc); PG_RETURN_XML_P(vardata); #else @@ -323,9 +329,10 @@ xml_out_internal(xmltype *x, pg_enc target_encoding) return buf.data; } - xml_ereport_by_code(WARNING, ERRCODE_INTERNAL_ERROR, - "could not parse XML declaration in stored value", - res_code); + ereport(WARNING, + errcode(ERRCODE_INTERNAL_ERROR), + errmsg_internal("could not parse XML declaration in stored value"), + errdetail_for_xml_code(res_code)); #endif return str; } @@ -392,7 +399,7 @@ xml_recv(PG_FUNCTION_ARGS) * Parse the data to check if it is well-formed XML data. Assume that * xml_parse will throw ERROR if not. */ - doc = xml_parse(result, xmloption, true, encoding); + doc = xml_parse(result, xmloption, true, encoding, NULL); xmlFreeDoc(doc); /* Now that we know what we're dealing with, convert to server encoding */ @@ -754,7 +761,7 @@ xmlparse(text *data, XmlOptionType xmloption_arg, bool preserve_whitespace) xmlDocPtr doc; doc = xml_parse(data, xmloption_arg, preserve_whitespace, - GetDatabaseEncoding()); + GetDatabaseEncoding(), NULL); xmlFreeDoc(doc); return (xmltype *) data; @@ -895,7 +902,7 @@ xml_is_document(xmltype *arg) PG_TRY(); { doc = xml_parse((text *) arg, XMLOPTION_DOCUMENT, true, - GetDatabaseEncoding()); + GetDatabaseEncoding(), NULL); result = true; } PG_CATCH(); @@ -1500,17 +1507,26 @@ xml_doctype_in_content(const xmlChar *str) /* - * Convert a C string to XML internal representation + * Convert a text object to XML internal representation + * + * data is the source data (must not be toasted!), encoding is its encoding, + * and xmloption_arg and preserve_whitespace are options for the + * transformation. + * + * Errors normally result in ereport(ERROR), but if escontext is an + * ErrorSaveContext, then "safe" errors are reported there instead, and the + * caller must check SOFT_ERROR_OCCURRED() to see whether that happened. * * Note: it is caller's responsibility to xmlFreeDoc() the result, - * else a permanent memory leak will ensue! + * else a permanent memory leak will ensue! But note the result could + * be NULL after a soft error. * * TODO maybe libxml2's xmlreader is better? (do not construct DOM, * yet do not use SAX - see xmlreader.c) */ static xmlDocPtr xml_parse(text *data, XmlOptionType xmloption_arg, bool preserve_whitespace, - int encoding) + int encoding, Node *escontext) { int32 len; xmlChar *string; @@ -1519,9 +1535,20 @@ xml_parse(text *data, XmlOptionType xmloption_arg, bool preserve_whitespace, volatile xmlParserCtxtPtr ctxt = NULL; volatile xmlDocPtr doc = NULL; + /* + * This step looks annoyingly redundant, but we must do it to have a + * null-terminated string in case encoding conversion isn't required. + */ len = VARSIZE_ANY_EXHDR(data); /* will be useful later */ string = xml_text2xmlChar(data); + /* + * If the data isn't UTF8, we must translate before giving it to libxml. + * + * XXX ideally, we'd catch any encoding conversion failure and return a + * soft error. However, failure to convert to UTF8 should be pretty darn + * rare, so for now this is left undone. + */ utf8string = pg_do_encoding_conversion(string, len, encoding, @@ -1539,6 +1566,7 @@ xml_parse(text *data, XmlOptionType xmloption_arg, bool preserve_whitespace, xmlChar *version = NULL; int standalone = 0; + /* Any errors here are reported as hard ereport's */ xmlInitParser(); ctxt = xmlNewParserCtxt(); @@ -1555,9 +1583,13 @@ xml_parse(text *data, XmlOptionType xmloption_arg, bool preserve_whitespace, res_code = parse_xml_decl(utf8string, &count, &version, NULL, &standalone); if (res_code != 0) - xml_ereport_by_code(ERROR, ERRCODE_INVALID_XML_CONTENT, - "invalid XML content: invalid XML declaration", - res_code); + { + errsave(escontext, + errcode(ERRCODE_INVALID_XML_CONTENT), + errmsg_internal("invalid XML content: invalid XML declaration"), + errdetail_for_xml_code(res_code)); + goto fail; + } /* Is there a DOCTYPE element? */ if (xml_doctype_in_content(utf8string + count)) @@ -1580,20 +1612,30 @@ xml_parse(text *data, XmlOptionType xmloption_arg, bool preserve_whitespace, | (preserve_whitespace ? 0 : XML_PARSE_NOBLANKS)); if (doc == NULL || xmlerrcxt->err_occurred) { - /* Use original option to decide which error code to throw */ + /* Use original option to decide which error code to report */ if (xmloption_arg == XMLOPTION_DOCUMENT) - xml_ereport(xmlerrcxt, ERROR, ERRCODE_INVALID_XML_DOCUMENT, + xml_errsave(escontext, xmlerrcxt, + ERRCODE_INVALID_XML_DOCUMENT, "invalid XML document"); else - xml_ereport(xmlerrcxt, ERROR, ERRCODE_INVALID_XML_CONTENT, + xml_errsave(escontext, xmlerrcxt, + ERRCODE_INVALID_XML_CONTENT, "invalid XML content"); + goto fail; } } else { doc = xmlNewDoc(version); + if (doc == NULL || xmlerrcxt->err_occurred) + xml_ereport(xmlerrcxt, ERROR, ERRCODE_OUT_OF_MEMORY, + "could not allocate XML document"); + Assert(doc->encoding == NULL); doc->encoding = xmlStrdup((const xmlChar *) "UTF-8"); + if (doc->encoding == NULL || xmlerrcxt->err_occurred) + xml_ereport(xmlerrcxt, ERROR, ERRCODE_OUT_OF_MEMORY, + "could not allocate XML document"); doc->standalone = standalone; /* allow empty content */ @@ -1602,10 +1644,17 @@ xml_parse(text *data, XmlOptionType xmloption_arg, bool preserve_whitespace, res_code = xmlParseBalancedChunkMemory(doc, NULL, NULL, 0, utf8string + count, NULL); if (res_code != 0 || xmlerrcxt->err_occurred) - xml_ereport(xmlerrcxt, ERROR, ERRCODE_INVALID_XML_CONTENT, + { + xml_errsave(escontext, xmlerrcxt, + ERRCODE_INVALID_XML_CONTENT, "invalid XML content"); + goto fail; + } } } + +fail: + ; } PG_CATCH(); { @@ -1745,6 +1794,44 @@ xml_ereport(PgXmlErrorContext *errcxt, int level, int sqlcode, const char *msg) } +/* + * xml_errsave --- save an XML-related error + * + * If escontext is an ErrorSaveContext, error details are saved into it, + * and control returns normally. + * + * Otherwise, the error is thrown, so that this is equivalent to + * xml_ereport() with level == ERROR. + * + * This should be used only for errors that we're sure we do not need + * a transaction abort to clean up after. + */ +static void +xml_errsave(Node *escontext, PgXmlErrorContext *errcxt, + int sqlcode, const char *msg) +{ + char *detail; + + /* Defend against someone passing us a bogus context struct */ + if (errcxt->magic != ERRCXT_MAGIC) + elog(ERROR, "xml_errsave called with invalid PgXmlErrorContext"); + + /* Flag that the current libxml error has been reported */ + errcxt->err_occurred = false; + + /* Include detail only if we have some text from libxml */ + if (errcxt->err_buf.len > 0) + detail = errcxt->err_buf.data; + else + detail = NULL; + + errsave(escontext, + (errcode(sqlcode), + errmsg_internal("%s", msg), + detail ? errdetail_internal("%s", detail) : 0)); +} + + /* * Error handler for libxml errors and warnings */ @@ -1917,15 +2004,16 @@ xml_errorHandler(void *data, xmlErrorPtr error) /* - * Wrapper for "ereport" function for XML-related errors. The "msg" - * is the SQL-level message; some can be adopted from the SQL/XML - * standard. This function uses "code" to create a textual detail - * message. At the moment, we only need to cover those codes that we + * Convert libxml error codes into textual errdetail messages. + * + * This should be called within an ereport or errsave invocation, + * just as errdetail would be. + * + * At the moment, we only need to cover those codes that we * may raise in this file. */ -static void -xml_ereport_by_code(int level, int sqlcode, - const char *msg, int code) +static int +errdetail_for_xml_code(int code) { const char *det; @@ -1954,10 +2042,7 @@ xml_ereport_by_code(int level, int sqlcode, break; } - ereport(level, - (errcode(sqlcode), - errmsg_internal("%s", msg), - errdetail(det, code))); + return errdetail(det, code); } @@ -4241,7 +4326,7 @@ wellformed_xml(text *data, XmlOptionType xmloption_arg) /* We want to catch any exceptions and return false */ PG_TRY(); { - doc = xml_parse(data, xmloption_arg, true, GetDatabaseEncoding()); + doc = xml_parse(data, xmloption_arg, true, GetDatabaseEncoding(), NULL); result = true; } PG_CATCH(); diff --git a/src/test/regress/expected/xml.out b/src/test/regress/expected/xml.out index 948b4e702c..a672e24dae 100644 --- a/src/test/regress/expected/xml.out +++ b/src/test/regress/expected/xml.out @@ -18,6 +18,37 @@ SELECT * FROM xmltest; 2 | two (2 rows) +-- test non-throwing API, too +SELECT pg_input_is_valid('one', 'xml'); + pg_input_is_valid +------------------- + t +(1 row) + +SELECT pg_input_is_valid('oneone', 'xml'); + pg_input_is_valid +------------------- + f +(1 row) + +SELECT pg_input_error_message('', 'xml'); + pg_input_error_message +---------------------------------------------- + invalid XML content: invalid XML declaration +(1 row) + SELECT xmlcomment('test'); xmlcomment ------------- diff --git a/src/test/regress/sql/xml.sql b/src/test/regress/sql/xml.sql index 484e3637e4..ddff459297 100644 --- a/src/test/regress/sql/xml.sql +++ b/src/test/regress/sql/xml.sql @@ -9,6 +9,13 @@ INSERT INTO xmltest VALUES (3, 'one', 'xml'); +SELECT pg_input_is_valid('oneone', 'xml'); +SELECT pg_input_error_message('', 'xml'); + SELECT xmlcomment('test'); SELECT xmlcomment('-test');