Re: [PATCH for 7.4.0] conf: Avoid double indentation of <metadata/> element

Michal Privoznik <mprivozn(a)redhat.com&gt; [2021-05-25, 09:32AM +0200]: > There was a recent change in libxml2 that caused a trouble for > us. To us, <metadata/> in domain or network XMLs are just opaque > value where management application can store whatever data it > finds fit. At XML parser/formatter level, we just make a copy of > the element during parsing and then format it back. For > formatting we use xmlNodeDump() which allows caller to specify > level of indentation. Previously, the indentation was not > applied onto the very first line, but as of v2.9.12-2-g85b1792e > libxml2 is applying indentation also on the first line. > > This does not work well with out virBuffer because as soon as we > call virBufferAsprintf() to append <metadata/> element, > virBufferAsprintf() will apply another level of indentation. > > Instead of version checking, let's skip any indentation added by > libxml2 before virBufferAsprintf() is called. > > Note, the problem is only when telling xmlNodeDump() to use > indentation, i.e. level argument is not zero. Therefore, > virXMLNodeToString() which also calls xmlNodeDump() is safe as it > passes zero. > > Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; Tested-by: Bjoern Walk <bwalk(a)linux.ibm.com&gt; But like Daniel said, this now breaks for older libxml2 versions.