From 68d1056392dcac7a0a825680e9efee3e6519c6e0 Mon Sep 17 00:00:00 2001
From: Peter Krempa <pkrempa@redhat.com>
Date: Mon, 28 Mar 2022 16:00:58 +0200
Subject: [PATCH] virXMLFormatElement: Introduce virXMLFormatElementInternal
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The new function aggregates the internal working of virXMLFormatElement
and virXMLFormatElementEmpty and also allows skipping the newline
after the opening tag to allow using this helper also in cases where we
don't format any child elements but directly a value.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
---
 src/libvirt_private.syms |  1 +
 src/util/virxml.c        | 58 +++++++++++++++++++++++++++++++---------
 src/util/virxml.h        |  7 +++++
 3 files changed, 54 insertions(+), 12 deletions(-)

diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index a9d7ed972f..97bfca906b 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -3634,6 +3634,7 @@ virXMLCheckIllegalChars;
 virXMLExtractNamespaceXML;
 virXMLFormatElement;
 virXMLFormatElementEmpty;
+virXMLFormatElementInternal;
 virXMLFormatMetadata;
 virXMLNewNode;
 virXMLNodeContentString;
diff --git a/src/util/virxml.c b/src/util/virxml.c
index e9ccb54c41..12b2ef635a 100644
--- a/src/util/virxml.c
+++ b/src/util/virxml.c
@@ -1609,21 +1609,48 @@ virXMLValidatorFree(virXMLValidator *validator)
 }
 
 
-/* same as virXMLFormatElement but outputs an empty element if @attrBuf and
- * @childBuf are both empty */
+/**
+ * virXMLFormatElementInternal
+ * @buf: the parent buffer where the element will be placed
+ * @name: the name of the element
+ * @attrBuf: buffer with attributes for element, may be NULL
+ * @childBuf: buffer with child elements, may be NULL
+ * @allowEmpty: Format empty element if @attrBuf and @childBuf are empty
+ * @childNewline: Add a newline after the opening element before formatting @childBuf
+ *
+ * Helper to format element where attributes or child elements
+ * are optional and may not be formatted.  If both @attrBuf and
+ * @childBuf are NULL or are empty buffers the element is not
+ * formatted.
+ *
+ * Passing false for @childNewline allows to format elements where we directly
+ * output a value without subelements.
+ *
+ * Both passed buffers are always consumed and freed.
+ */
 void
-virXMLFormatElementEmpty(virBuffer *buf,
-                         const char *name,
-                         virBuffer *attrBuf,
-                         virBuffer *childBuf)
+virXMLFormatElementInternal(virBuffer *buf,
+                            const char *name,
+                            virBuffer *attrBuf,
+                            virBuffer *childBuf,
+                            bool allowEmpty,
+                            bool childNewline)
 {
+    if (!allowEmpty) {
+        if ((!attrBuf || virBufferUse(attrBuf) == 0) &&
+            (!childBuf || virBufferUse(childBuf) == 0))
+            return;
+    }
+
     virBufferAsprintf(buf, "<%s", name);
 
     if (attrBuf && virBufferUse(attrBuf) > 0)
         virBufferAddBuffer(buf, attrBuf);
 
     if (childBuf && virBufferUse(childBuf) > 0) {
-        virBufferAddLit(buf, ">\n");
+        virBufferAddLit(buf, ">");
+        if (childNewline)
+            virBufferAddLit(buf, "\n");
         virBufferAddBuffer(buf, childBuf);
         virBufferAsprintf(buf, "</%s>\n", name);
     } else {
@@ -1634,6 +1661,17 @@ virXMLFormatElementEmpty(virBuffer *buf,
     virBufferFreeAndReset(childBuf);
 }
 
+/* same as virXMLFormatElement but outputs an empty element if @attrBuf and
+ * @childBuf are both empty */
+void
+virXMLFormatElementEmpty(virBuffer *buf,
+                         const char *name,
+                         virBuffer *attrBuf,
+                         virBuffer *childBuf)
+{
+    virXMLFormatElementInternal(buf, name, attrBuf, childBuf, true, true);
+}
+
 
 /**
  * virXMLFormatElement
@@ -1655,11 +1693,7 @@ virXMLFormatElement(virBuffer *buf,
                     virBuffer *attrBuf,
                     virBuffer *childBuf)
 {
-    if ((!attrBuf || virBufferUse(attrBuf) == 0) &&
-        (!childBuf || virBufferUse(childBuf) == 0))
-        return;
-
-    virXMLFormatElementEmpty(buf, name, attrBuf, childBuf);
+    virXMLFormatElementInternal(buf, name, attrBuf, childBuf, false, true);
 }
 
 
diff --git a/src/util/virxml.h b/src/util/virxml.h
index 05016db577..5d49056bc7 100644
--- a/src/util/virxml.h
+++ b/src/util/virxml.h
@@ -322,6 +322,13 @@ void
 virXMLValidatorFree(virXMLValidator *validator);
 G_DEFINE_AUTOPTR_CLEANUP_FUNC(virXMLValidator, virXMLValidatorFree);
 
+void
+virXMLFormatElementInternal(virBuffer *buf,
+                            const char *name,
+                            virBuffer *attrBuf,
+                            virBuffer *childBuf,
+                            bool allowEmpty,
+                            bool childNewline);
 void
 virXMLFormatElement(virBuffer *buf,
                     const char *name,