2017-10-17 1:57 GMT+02:00 Noah Misch <n...@leadboat.com>: > On Sun, Aug 20, 2017 at 10:37:10PM +0200, Pavel Stehule wrote: > > > We have xpath-bugfix.patch and xpath-parsing-error-fix.patch. Both are > > > equivalent under supported use cases (xpath in UTF8 databases). Among > > > non-supported use cases, they each make different things better and > > > different > > > things worse. We should prefer to back-patch the version harming fewer > > > applications. I expect non-ASCII data is more common than xml > declarations > > > with "encoding" attribute, so xpath-bugfix.patch will harm fewer > > > applications. > > > > > > Having said that, I now see a third option. Condition this thread's > > > patch's > > > effects on GetDatabaseEncoding()==PG_UTF8. That way, we fix supported > > > cases, > > > and we remain bug-compatible in unsupported cases. I think that's > better > > > than > > > the other options discussed so far. If you agree, please send a patch > > > based > > > on xpath-bugfix.patch with the GetDatabaseEncoding()==PG_UTF8 change > and > > > the > > > two edits I described earlier. > > > > > > > I am sorry - too long day today. Do you think some like > > > > diff --git a/src/backend/utils/adt/xml.c b/src/backend/utils/adt/xml.c > > index 24229c2dff..9fd6f3509f 100644 > > --- a/src/backend/utils/adt/xml.c > > +++ b/src/backend/utils/adt/xml.c > > @@ -3914,7 +3914,14 @@ 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); > > + > > + /* > > + * Passed XML is always in server encoding. When server encoding > > + * is UTF8, we can pass this information to libxml2 to ignore > > + * possible invalid encoding declaration in XML document. > > + */ > > + doc = xmlCtxtReadMemory(ctxt, (char *) string, len, NULL, > > + GetDatabaseEncoding() == PG_UTF8 ? "UTF-8" : NULL, 0); > > if (doc == NULL || xmlerrcxt->err_occurred) > > xml_ereport(xmlerrcxt, ERROR, ERRCODE_INVALID_XML_DOCUMENT, > > "could not parse XML document"); > > No, that doesn't match my description above. I don't see a way to clarify > the > description. Feel free to try again. Alternately, if you wait, I will > eventually construct the patch I described. >
Please, if you can, try it write. I am little bit lost :) Regards Pavel
