[libxml2] Fix various problems with "make dist"

[Daniel Veillard <veillard src gnome org>]

commit 79ee284abbe4536a5045b4d9ac9412a2e2d0dead
Author: Daniel Veillard <veillard redhat com>
Date:   Tue May 15 10:25:31 2012 +0800

    Fix various problems with "make dist"
    
    * tree.c: missing documentation for xmlBufferDetach
    * doc/symbols.xml: add two new symbols xmlTextReaderRelaxNGValidateCtxt
                       and xmlBufferDetach
    * doc/apibuild.py: ignore internal header xzlib.h

 doc/apibuild.py |    1 +
 doc/symbols.xml |    4 ++++
 tree.c          |    6 ++++--
 3 files changed, 9 insertions(+), 2 deletions(-)
---
diff --git a/doc/apibuild.py b/doc/apibuild.py
index 5bfe68f..c2dff84 100755
--- a/doc/apibuild.py
+++ b/doc/apibuild.py
@@ -52,6 +52,7 @@ ignored_files = {
   "test.c": "not part of the library",
   "testdso.c": "test for dynamid shared libraries",
   "testrecurse.c": "test for entities recursions",
+  "xzlib.h": "Internal API only",
 }
 
 ignored_words = {
diff --git a/doc/symbols.xml b/doc/symbols.xml
index b4d9082..56a1877 100644
--- a/doc/symbols.xml
+++ b/doc/symbols.xml
@@ -1741,4 +1741,8 @@
     <symbol file="globals">xmlStructuredErrorContext</symbol>
     <symbol file="xinclude">xmlXIncludeProcessTreeFlagsData</symbol>
   </release>
+  <release version="2.7.9">
+    <symbol file="xmlreader">xmlTextReaderRelaxNGValidateCtxt</symbol>
+    <symbol file="tree">xmlBufferDetach</symbol>
+  </release>
 </symbols>
diff --git a/tree.c b/tree.c
index 47b906c..a75a707 100644
--- a/tree.c
+++ b/tree.c
@@ -6934,11 +6934,13 @@ xmlBufferCreateSize(size_t size) {
 }
 
 /**
- * xmlBufferDetach
+ * xmlBufferDetach:
  * @buf:  the buffer
  *
- * Returns the previous string contained by the buffer.
+ * Remove the string contained in a buffer and gie it back to the
+ * caller. The buffer is reset to an emoty content.
  *
+ * Returns the previous string contained by the buffer.
  */
 xmlChar *
 xmlBufferDetach(xmlBufferPtr buf) {