Deprecate KeepBlanks global in libxml 2.14.0+

Author: dwarring

src/xml6_gbl.c

@@ -67,11 +67,17 @@ DLLEXPORT void xml6_gbl_os_thread_set_tag_expansion(int flag) {
 }
 
 DLLEXPORT int xml6_gbl_os_thread_get_keep_blanks(void) {
+#ifdef XML6_GBL_COMPAT_KEEP_BLANKS
     return xmlKeepBlanksDefaultValue;
+#else
+    return -1;
+#endif
 }
 
 DLLEXPORT void xml6_gbl_os_thread_set_keep_blanks(int flag) {
+#ifdef XML6_GBL_COMPAT_KEEP_BLANKS
     xmlKeepBlanksDefaultValue = flag;
+#endif
 }
 
 DLLEXPORT void xml6_gbl_os_thread_xml_free(void* obj) {

src/xml6_gbl.h

@@ -8,6 +8,9 @@
 # define XML6_GBL_COMPAT_OLD_ERRORS 1
 #endif
 
+#if LIBXML_VERSION < 21400
+# define XML6_GBL_COMPAT_KEEP_BLANKS 1
+#endif
 
 DLLEXPORT void xml6_gbl_init(void);