Fix for vista (#21)

* Use old libs on Vista

* Update NEWS

Author: jeroen

NEWS

@@ -1,3 +1,13 @@
+1.6.6-1
+  - Fix build on legacy Windows Vista (i.e. the old winbuilder machine)
+
+1.6.6
+  - Update vendored gifski to upstream 1.6.6
+  - Note gifski 1.6.6 requires at least Rust 1.56. On older systems we fall
+    back on the previous gifski 1.4.3 version.
+  - New rust also does not work on Windows Vista / 2008 anymore (i.e. the
+    old cran winbuilder). So on this machine we also fall back on 1.4.3.
+
 1.4.3-1:
   - Add libgifski ucrt64 binary
 

src/Makevars.win.static

@@ -1,5 +1,5 @@
 VERSION = 1.6.6
-RWINLIB = ../windows/gifski-$(VERSION)
+RWINLIB = ../windows/gifski-winlibs
 PKG_CPPFLAGS = -I$(RWINLIB)/include
 PKG_LIBS = -L$(RWINLIB)/lib${R_ARCH}${CRT} \
 	-lgifski -lws2_32 -ladvapi32 -luserenv -ldbghelp -lbcrypt

tools/winlibs.R

@@ -1,9 +1,16 @@
 # Build against gifski libs compiled with the Rtools
 VERSION <- commandArgs(TRUE)
+
+# Hack: latest gifski does not work on Windows Vista
+if(grepl('Windows (Vista|Server 2008)', osVersion)){
+  VERSION <- '1.4.3'
+}
+
 if(!file.exists(sprintf("../windows/gifski-%s/include/gifski.h", VERSION))){
   if(getRversion() < "3.3.0") setInternet2()
   download.file(sprintf("https://github.com/rwinlib/gifski/archive/v%s.zip", VERSION), "lib.zip", quiet = TRUE)
   dir.create("../windows", showWarnings = FALSE)
   unzip("lib.zip", exdir = "../windows")
   unlink("lib.zip")
+  file.rename(sprintf("../windows/gifski-%s", VERSION), '../windows/gifski-winlibs')
 }