orcus: underscores are allowed as starting character in xml names

Change-Id: Ib379831bb0725d97bc79681af7a2052ccd553c79
Reviewed-on: https://gerrit.libreoffice.org/41081Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Markus Mohrhard <markus.mohrhard@googlemail.com>

external/liborcus/UnpackedTarball_liborcus.mk

@@ -20,6 +20,7 @@ $(eval $(call gb_UnpackedTarball_add_patches,liborcus,\
 	external/liborcus/iOS.patch \
 	external/liborcus/nullptr-in-ostringstream.patch.1 \
 	external/liborcus/orcus_allow_missing_xml_header.patch.1 \
+	external/liborcus/orcus_allow_underscore_in_names.patch.1 \
 ))
 
 ifeq ($(OS),WNT)

external/liborcus/orcus_allow_underscore_in_names.patch.1

+diff -ur liborcus.org/src/parser/sax_parser_base.cpp liborcus/src/parser/sax_parser_base.cpp
+--- liborcus.org/src/parser/sax_parser_base.cpp	2017-08-12 10:39:49.963174114 +0200
++++ liborcus/src/parser/sax_parser_base.cpp	2017-08-12 10:41:32.026899749 +0200
+@@ -334,7 +334,7 @@
+ {
+     const char* p0 = mp_char;
+     char c = cur_char();
+-    if (!is_alpha(c))
++    if (!is_alpha(c) && c != '_')
+     {
+         ::std::ostringstream os;
+         os << "name must begin with an alphabet, but got this instead '" << c << "'";