Windows: upgrade to libxml2 2.9.8

.gitignore

@@ -9,3 +9,4 @@ src/Makevars
 inst/doc
 script.R
 TODO.md
+windows

NEWS.md

@@ -4,6 +4,8 @@
 
 * xml2 now has a pkgdown site! <http://xml2.r-lib.org> (@jayhesselberth, #211).
 
+* Windows: upgrade to libxml2 2.9.8
+
 ## Bugfixes
 
 * Generic xml2 error are now forwarded as R errors. Previously these errors

src/Makevars.win

@@ -1,14 +1,16 @@
-PKG_CPPFLAGS=-I../inst/include -I../windows/libxml2-2.9.4/include/libxml2 \
+VERSION=2.9.8
+RWINLIB=../windows/libxml2-$(VERSION)
+PKG_CPPFLAGS=-I../inst/include -I$(RWINLIB)/include/libxml2 \
 	-DLIBXML_STATIC
 
-PKG_LIBS=-L../windows/libxml2-2.9.4/lib${R_ARCH} -lxml2 -llzma -liconv -lz -lws2_32
+PKG_LIBS=-L$(RWINLIB)/lib${R_ARCH} -lxml2 -llzma -liconv -lz -lws2_32
 
 all: clean winlibs
 
 clean:
 	rm -f $(OBJECTS) $(SHLIB)
 
 winlibs:
-	"${R_HOME}/bin${R_ARCH_BIN}/Rscript.exe" --vanilla "../tools/winlibs.R"
+	"${R_HOME}/bin${R_ARCH_BIN}/Rscript.exe" --vanilla "../tools/winlibs.R" $(VERSION)
 
 .PHONY: all winlibs clean

tools/winlibs.R

@@ -1,7 +1,8 @@
-# Build against libxml2 from Rtools
-if (!file.exists("../windows/libxml2-2.9.4/include/libxml2/libxml/parser.h")) {
+# Build against static libraries from rwinlib
+VERSION <- commandArgs(TRUE)
+if(!file.exists(sprintf("../windows/libxml2-%s/include/libxml2/libxml/parser.h", VERSION))){
   if(getRversion() < "3.3.0") setInternet2()
-  download.file("https://github.com/rwinlib/libxml2/archive/v2.9.4.zip", "lib.zip", quiet = TRUE)
+  download.file(sprintf("https://github.com/rwinlib/libxml2/archive/v%s.zip", VERSION), "lib.zip", quiet = TRUE)
   dir.create("../windows", showWarnings = FALSE)
   unzip("lib.zip", exdir = "../windows")
   unlink("lib.zip")