+libxslt (#395)

* add libxslt

* fix libxslt test

* fix libxslt test

* fix libxslt test

* build w/ libxml2 include prefix

* add libxml2 prefix to inlcude

* restart ci

* test fix

* use pkg-config

* fix

* wip

* wip

* wip

* wip

---------

Co-authored-by: Max Howell <mxcl@me.com>

.gitignore

@@ -1 +1,3 @@
 /tea.out
+/tea.linux
+.DS_Store

projects/gnome.org/libxslt/package.yml

@@ -0,0 +1,45 @@
+distributable:
+  url: https://download.gnome.org/sources/libxslt/{{ version.marketing }}/libxslt-{{ version }}.tar.xz
+  strip-components: 1
+
+versions:
+  github: GNOME/libxslt/tags
+
+dependencies:
+  gnome.org/libxml2: '*'
+
+build:
+  dependencies:
+    freedesktop.org/pkg-config: ^0.29
+    tea.xyz/gx/cc: c99
+    tea.xyz/gx/make: '*'
+    gnu.org/patch: '*'
+  script: |
+    patch -p1 < props/xslt-config.patch.in
+
+    ./configure $ARGS
+    make --jobs {{ hw.concurrency }}
+    make install
+
+    cd "{{prefix}}/bin"
+    sed -i.bak \
+      -e 's|{{prefix}}|"$prefix"|g' \
+      -e 's|{{deps.gnome.org/libxml2.prefix}}|""$libxml2_prefix""|g' \
+      xslt-config
+    rm xslt-config.bak
+  env:
+    ARGS:
+      - --prefix={{prefix}}
+      - --without-python   # we don’t yet know how to support this
+      - --without-plugins  # doesn’t build and we couldn’t debug
+
+test:
+  dependencies:
+    tea.xyz/gx/cc: c99
+  script: |
+    cc `xslt-config --cflags --libs` test.c
+    ./a.out
+
+provides:
+  - bin/xslt-config
+  - bin/xsltproc

projects/gnome.org/libxslt/test.c

@@ -0,0 +1,13 @@
+#include <libxml/parser.h>
+#include <libxslt/xslt.h>
+#include <libxslt/xsltInternals.h>
+
+
+int main() {
+  xmlDocPtr doc = xmlNewDoc(BAD_CAST "1.0");
+  xsltStylesheetPtr cur = NULL;
+  cur = xsltLoadStylesheetPI(doc);
+  xsltFreeStylesheet(cur);
+  xmlFreeDoc(doc);
+  return 0;
+}

projects/gnome.org/libxslt/xslt-config.patch.in

@@ -0,0 +1,13 @@
+diff --git a/xslt-config.in b/xslt-config.in
+index f68df0f..b9bd2f4 100644
+--- a/xslt-config.in
++++ b/xslt-config.in
+@@ -1,6 +1,7 @@
+ #! /bin/sh
+
+-prefix=@prefix@
++prefix="$(cd "$(dirname "$0")/.." && pwd)"
++libxml2_prefix="$(cd "$prefix/../../libxml2/v2" && pwd)"
+ exec_prefix=@exec_prefix@
+ exec_prefix_set=no
+ includedir=@includedir@