On 2019-Mar-08, Pavel Stehule wrote: > looks like error in xmlXPathCompiledEval function, that produce little bit > broken result for XML_DOCUMENT_NODE type. I hadn't this problem with > libxml2 2.7.6 64bit, but I seen this issue on same version on 32bit. > > Currently I had not fresh 32 bit system to check it. > > I found a workaround - in this case copy (and release xmlNode) is not > necessary. > > please, apply attached patch.
Wow :-( At this point I'm wondering if this should be put in back branches as well ... I mean, distill part of commit 251cf2e27bec that doesn't affect the behavior of text nodes, and put it on all branches together with your fix? Another thought: should we refuse to work on known-broken libxml2 versions? Seems like this bug could affect other parts of code too -- I see that xmlXPathCompiledEval() is called in file places (including two in contrib/xml2). Third thought: an alternative might be to create a wrapper for xmlXPathCompiledEval that detects NULL content and fills in a pointer that xmlFreeNode can free. -- Álvaro Herrera https://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
