So far, we have to places where we format <metadata/> into XMLs: domain and network. Bot places share the same code. Move it into a helper function and just call it from those places. Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; --- src/conf/domain_conf.c | 23 ++------------------- src/conf/network_conf.c | 23 ++------------------- src/libvirt_private.syms | 1 + src/util/virxml.c | 43 ++++++++++++++++++++++++++++++++++++++++ src/util/virxml.h | 3 +++ 5 files changed, 51 insertions(+), 42 deletions(-) diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index 4f78b7b43d..413c44ac61 100644 --- a/src/conf/domain_conf.c +++ b/src/conf/domain_conf.c @@ -27806,27 +27806,8 @@ virDomainDefFormatInternalSetRootName(virDomainDef *def, virBufferEscapeString(buf, "<description>%s</description>\n", def->description); - if (def->metadata) { - g_autoptr(xmlBuffer) xmlbuf = NULL; - int oldIndentTreeOutput = xmlIndentTreeOutput; - - /* Indentation on output requires that we previously set - * xmlKeepBlanksDefault to 0 when parsing; also, libxml does 2 - * spaces per level of indentation of intermediate elements, - * but no leading indentation before the starting element. - * Thankfully, libxml maps what looks like globals into - * thread-local uses, so we are thread-safe. */ - xmlIndentTreeOutput = 1; - xmlbuf = virXMLBufferCreate(); - - if (xmlNodeDump(xmlbuf, def->metadata->doc, def->metadata, - virBufferGetIndent(buf) / 2, 1) < 0) { - xmlIndentTreeOutput = oldIndentTreeOutput; - return -1; - } - virBufferAsprintf(buf, "%s\n", (char *) xmlBufferContent(xmlbuf)); - xmlIndentTreeOutput = oldIndentTreeOutput; - } + if (virXMLFormatMetadata(buf, def->metadata) < 0) + return -1; if (virDomainDefHasMemoryHotplug(def)) { virBufferAsprintf(buf, diff --git a/src/conf/network_conf.c b/src/conf/network_conf.c index a9eadff29c..b10ff5c7a8 100644 --- a/src/conf/network_conf.c +++ b/src/conf/network_conf.c @@ -2486,27 +2486,8 @@ virNetworkDefFormatBuf(virBuffer *buf, virUUIDFormat(uuid, uuidstr); virBufferAsprintf(buf, "<uuid>%s</uuid>\n", uuidstr); - if (def->metadata) { - g_autoptr(xmlBuffer) xmlbuf = NULL; - int oldIndentTreeOutput = xmlIndentTreeOutput; - - /* Indentation on output requires that we previously set - * xmlKeepBlanksDefault to 0 when parsing; also, libxml does 2 - * spaces per level of indentation of intermediate elements, - * but no leading indentation before the starting element. - * Thankfully, libxml maps what looks like globals into - * thread-local uses, so we are thread-safe. */ - xmlIndentTreeOutput = 1; - xmlbuf = virXMLBufferCreate(); - - if (xmlNodeDump(xmlbuf, def->metadata->doc, def->metadata, - virBufferGetIndent(buf) / 2, 1) < 0) { - xmlIndentTreeOutput = oldIndentTreeOutput; - return -1; - } - virBufferAsprintf(buf, "%s\n", (char *) xmlBufferContent(xmlbuf)); - xmlIndentTreeOutput = oldIndentTreeOutput; - } + if (virXMLFormatMetadata(buf, def->metadata) < 0) + return -1; if (def->forward.type != VIR_NETWORK_FORWARD_NONE) { const char *dev = NULL; diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms index e1aef5267e..37515f80ec 100644 --- a/src/libvirt_private.syms +++ b/src/libvirt_private.syms @@ -3555,6 +3555,7 @@ virXMLCheckIllegalChars; virXMLExtractNamespaceXML; virXMLFormatElement; virXMLFormatElementEmpty; +virXMLFormatMetadata; virXMLNewNode; virXMLNodeContentString; virXMLNodeNameEqual; diff --git a/src/util/virxml.c b/src/util/virxml.c index 8dcece704a..062a5402f6 100644 --- a/src/util/virxml.c +++ b/src/util/virxml.c @@ -1707,6 +1707,49 @@ virXMLFormatElement(virBuffer *buf, } +/** + * virXMLFormatMetadata: + * @buf: the parent buffer where the element will be placed + * @metadata: pointer to metadata node + * + * Helper to format metadata element. If @metadata is NULL then + * this function is a NOP. + * + * Returns: 0 on success, + * -1 otherwise. + */ +int +virXMLFormatMetadata(virBuffer *buf, + xmlNodePtr metadata) +{ + g_autoptr(xmlBuffer) xmlbuf = NULL; + int oldIndentTreeOutput = xmlIndentTreeOutput; + + if (!metadata) + return 0; + + /* Indentation on output requires that we previously set + * xmlKeepBlanksDefault to 0 when parsing; also, libxml does 2 + * spaces per level of indentation of intermediate elements, + * but no leading indentation before the starting element. + * Thankfully, libxml maps what looks like globals into + * thread-local uses, so we are thread-safe. */ + xmlIndentTreeOutput = 1; + xmlbuf = virXMLBufferCreate(); + + if (xmlNodeDump(xmlbuf, metadata->doc, metadata, + virBufferGetIndent(buf) / 2, 1) < 0) { + xmlIndentTreeOutput = oldIndentTreeOutput; + return -1; + } + + virBufferAsprintf(buf, "%s\n", (char *) xmlBufferContent(xmlbuf)); + xmlIndentTreeOutput = oldIndentTreeOutput; + + return 0; +} + + void virXPathContextNodeRestore(virXPathContextNodeSave *save) { diff --git a/src/util/virxml.h b/src/util/virxml.h index ed02abd2e9..0bb0d1c118 100644 --- a/src/util/virxml.h +++ b/src/util/virxml.h @@ -333,6 +333,9 @@ virXMLFormatElementEmpty(virBuffer *buf, virBuffer *attrBuf, virBuffer *childBuf); +int +virXMLFormatMetadata(virBuffer *buf, + xmlNodePtr metadata); struct _virXPathContextNodeSave { xmlXPathContextPtr ctxt; -- 2.26.3

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. Tested-by: Bjoern Walk <bwalk(a)linux.ibm.com&gt; Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; --- src/util/virxml.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/src/util/virxml.c b/src/util/virxml.c index 91c6f6b02e..4360b15486 100644 --- a/src/util/virxml.c +++ b/src/util/virxml.c @@ -1723,6 +1723,7 @@ virXMLFormatMetadata(virBuffer *buf, xmlNodePtr metadata) { g_autoptr(xmlBuffer) xmlbuf = NULL; + const char *xmlbufContent = NULL; int oldIndentTreeOutput = xmlIndentTreeOutput; if (!metadata) @@ -1745,7 +1746,12 @@ virXMLFormatMetadata(virBuffer *buf, return -1; } - virBufferAsprintf(buf, "%s\n", (char *) xmlBufferContent(xmlbuf)); + /* After libxml2-v2.9.12-2-g85b1792e even the first line is indented. + * But virBufferAsprintf() also adds indentation. Skip one of them. */ + xmlbufContent = (const char *) xmlBufferContent(xmlbuf); + virSkipSpaces(&xmlbufContent); + + virBufferAsprintf(buf, "%s\n", xmlbufContent); xmlIndentTreeOutput = oldIndentTreeOutput; return 0; -- 2.26.3