This patch modifies error handling function for the XML parser provided
by libxml2.
Originaly only a line number and error message were logged. With this
new error handler function, the user is provided with a more complex
description of the parsing error.
Context of the error is printed in libXML2 style and filename of the
file, that caused the error is printed. Example of an parse error:
13:41:36.262: 16032: error : catchXMLError:706 :
/etc/libvirt/qemu/rh_bad.xml:58: Opening and ending tag mismatch: name
line 2 and domain
</domain>
---------^
Context of the error gives the user hints that may help to quickly
locate a corrupt xml file.
fixes BZs:
----------
Bug 708735 - [RFE] Show column and line on XML parsing error
https://bugzilla.redhat.com/show_bug.cgi?id=708735
Bug 726771 - libvirt does not specify problem file if persistent xml is
invalid
https://bugzilla.redhat.com/show_bug.cgi?id=726771
Often, we want to use XPath functions on the just-parsed document;
fold this into the parser function for convenience.
* src/util/xml.h (virXMLParseHelper): Add argument.
(virXMLParseStrHelper, virXMLParseFileHelper): Delete.
(virXMLParseCtxt, virXMLParseStringCtxt, virXMLParseFileCtxt): New
macros.
* src/libvirt_private.syms (xml.h): Remove deleted functions.
* src/util/xml.c (virXMLParseHelper): Add argument.
(virXMLParseStrHelper, virXMLParseFileHelper): Delete.
It was awkward having only int conversion in the virStrToLong family,
but only long conversion in the virXPath family. Make both families
support both types.
* src/util/util.h (virStrToLong_l, virStrToLong_ul): New
prototypes.
* src/util/xml.h (virXPathInt, virXPathUInt): Likewise.
* src/util/util.c (virStrToLong_l, virStrToLong_ul): New
functions.
* src/util/xml.c (virXPathInt, virXPathUInt): Likewise.
* src/libvirt_private.syms (util.h, xml.h): Export them.
This introduces a third option for clock offset synchronization,
that allows an arbitrary / variable adjustment to be set. In
essence the XML contains the time delta in seconds, relative to
UTC.
<clock offset='variable' adjustment='123465'/>
The difference from 'utc' mode, is that management apps should
track adjustments and preserve them at next reboot.
* docs/schemas/domain.rng: Schema for new clock mode
* src/conf/domain_conf.c, src/conf/domain_conf.h: Parse
new clock time delta
* src/libvirt_private.syms, src/util/xml.c, src/util/xml.h: Add
virXPathLongLong() method
virXPathNodeSet() could return -1 when doing an evaluation failure
due to xmlXPathEval() from libxml2 behaviour.
* src/util/xml.c: make sure we always return 0 unless the returned
XPath type is of the wrong type (meaning the query passed didn't
evaluate to a node set and code must be fixed)
* src/util/xml.c: The virXPath... function take extra care to preserve
the XPath context node (ctxt->node) but in the case of virXPathString
and virXPathBoolean they forgot to do this on the error path. This
patch fixes this and move all ctxt->node = relnode instuctions just
after the xmlXPathEval() to make sure this doesn't happen if this code
is modified.
