[libxml2] Reenable xz support by default

[Daniel Veillard <veillard src gnome org>]

commit 18b8988511b0954272cac4d6c3e6724f9dbf6e0a
Author: Daniel Veillard <veillard redhat com>
Date:   Tue Nov 3 15:46:29 2015 +0800

    Reenable xz support by default
    
    For https://bugzilla.gnome.org/show_bug.cgi?id=757466
    
    problem was introduced by commit f3f86ff465c92c79f834d7b981f3c7274a8bb5c8
    for https://bugzilla.gnome.org/show_bug.cgi?id=711026

 configure.ac |    3 +++
 xmlIO.c      |   12 ++++++------
 xzlib.c      |    6 ++++--
 3 files changed, 13 insertions(+), 8 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 14ac0a8..48e0577 100644
--- a/configure.ac
+++ b/configure.ac
@@ -445,6 +445,9 @@ else
                 fi],
                 [have_liblzma=no])
             LDFLAGS="${SAVE_LDFLAGS}"])
+    else
+       # we still need to check for lzma,h header
+       AC_CHECK_HEADERS([lzma.h])
     fi
 
     # Found the library via either method?
diff --git a/xmlIO.c b/xmlIO.c
index e628ab0..8b13184 100644
--- a/xmlIO.c
+++ b/xmlIO.c
@@ -1334,7 +1334,7 @@ xmlGzfileClose (void * context) {
 }
 #endif /* HAVE_ZLIB_H */
 
-#ifdef HAVE_LZMA_H
+#ifdef LIBXML_LZMA_ENABLED
 /************************************************************************
  *                                                                     *
  *             I/O for compressed file accesses                        *
@@ -1451,7 +1451,7 @@ xmlXzfileClose (void * context) {
     if (ret < 0) xmlIOErr(0, "xzclose()");
     return(ret);
 }
-#endif /* HAVE_LZMA_H */
+#endif /* LIBXML_LZMA_ENABLED */
 
 #ifdef LIBXML_HTTP_ENABLED
 /************************************************************************
@@ -2328,10 +2328,10 @@ xmlRegisterDefaultInputCallbacks(void) {
     xmlRegisterInputCallbacks(xmlGzfileMatch, xmlGzfileOpen,
                              xmlGzfileRead, xmlGzfileClose);
 #endif /* HAVE_ZLIB_H */
-#ifdef HAVE_LZMA_H
+#ifdef LIBXML_LZMA_ENABLED
     xmlRegisterInputCallbacks(xmlXzfileMatch, xmlXzfileOpen,
                              xmlXzfileRead, xmlXzfileClose);
-#endif /* HAVE_ZLIB_H */
+#endif /* LIBXML_LZMA_ENABLED */
 
 #ifdef LIBXML_HTTP_ENABLED
     xmlRegisterInputCallbacks(xmlIOHTTPMatch, xmlIOHTTPOpen,
@@ -2683,7 +2683,7 @@ __xmlParserInputBufferCreateFilename(const char *URI, xmlCharEncoding enc) {
 #endif
        }
 #endif
-#ifdef HAVE_LZMA_H
+#ifdef LIBXML_LZMA_ENABLED
        if ((xmlInputCallbackTable[i].opencallback == xmlXzfileOpen) &&
                (strcmp(URI, "-") != 0)) {
             ret->compressed = __libxml2_xzcompressed(context);
@@ -3350,7 +3350,7 @@ xmlParserInputBufferGrow(xmlParserInputBufferPtr in, int len) {
      * try to establish compressed status of input if not done already
      */
     if (in->compressed == -1) {
-#ifdef HAVE_LZMA_H
+#ifdef LIBXML_LZMA_ENABLED
        if (in->readcallback == xmlXzfileRead)
             in->compressed = __libxml2_xzcompressed(in->context);
 #endif
diff --git a/xzlib.c b/xzlib.c
index 1fab546..782957f 100644
--- a/xzlib.c
+++ b/xzlib.c
@@ -8,7 +8,7 @@
  */
 #define IN_LIBXML
 #include "libxml.h"
-#ifdef HAVE_LZMA_H
+#ifdef LIBXML_LZMA_ENABLED
 
 #include <string.h>
 #ifdef HAVE_ERRNO_H
@@ -34,7 +34,9 @@
 #ifdef HAVE_ZLIB_H
 #include <zlib.h>
 #endif
+#ifdef HAVE_LZMA_H
 #include <lzma.h>
+#endif
 
 #include "xzlib.h"
 #include <libxml/xmlmemory.h>
@@ -799,4 +801,4 @@ __libxml2_xzclose(xzFile file)
     xmlFree(state);
     return ret ? ret : LZMA_OK;
 }
-#endif /* HAVE_LZMA_H */
+#endif /* LIBXML_LZMA_ENABLED */