dev-python/pillow: Fix cross-compiling of 5.4.1

Normally you shouldn't add -I/usr/include or -L/usr/lib, even if it is
prepended with the SYSROOT, but Pillow's stupid build system checks
for headers with Python rather than the toolchain. Luckily only
minimal patching is needed.

Signed-off-by: James Le Cuirot <chewi@gentoo.org>
Package-Manager: Portage-2.3.49, Repoman-2.3.10

dev-python/pillow/files/pillow-5.4.1-pkg-config.patch

@@ -0,0 +1,28 @@
+diff -Naur a/setup.py b/setup.py
+--- a/setup.py	2019-01-06 12:12:16.000000000 +0000
++++ b/setup.py	2019-01-08 23:04:45.574698210 +0000
+@@ -197,12 +197,13 @@
+ 
+ def _pkg_config(name):
+     try:
++        command = os.environ.get('PKG_CONFIG', 'pkg-config')
+         command_libs = [
+-            'pkg-config',
++            command,
+             '--libs-only-L', name,
+         ]
+         command_cflags = [
+-            'pkg-config',
++            command,
+             '--cflags-only-I', name,
+         ]
+         if not DEBUG:
+@@ -298,7 +299,7 @@
+         _add_directory(include_dirs, "src/libImaging")
+ 
+         pkg_config = None
+-        if _cmd_exists('pkg-config'):
++        if _cmd_exists(os.environ.get('PKG_CONFIG', 'pkg-config')):
+             pkg_config = _pkg_config
+ 
+         #

dev-python/pillow/files/pillow-5.4.1-toolchain-paths.patch

@@ -0,0 +1,12 @@
+diff -Naur a/setup.py b/setup.py
+--- a/setup.py	2019-01-08 23:06:33.082873069 +0000
++++ b/setup.py	2019-01-08 23:06:47.707165225 +0000
+@@ -356,7 +356,7 @@
+                 for d in os.environ[k].split(os.path.pathsep):
+                     _add_directory(library_dirs, d)
+ 
+-        prefix = sysconfig.get_config_var("prefix")
++        prefix = None
+         if prefix:
+             _add_directory(library_dirs, os.path.join(prefix, "lib"))
+             _add_directory(include_dirs, os.path.join(prefix, "include"))

dev-python/pillow/pillow-5.4.1.ebuild

@@ -6,7 +6,7 @@ EAPI=7
 PYTHON_COMPAT=( python2_7 python3_{4,5,6,7} pypy )
 PYTHON_REQ_USE='tk?,threads(+)'
 
-inherit distutils-r1 virtualx
+inherit distutils-r1 toolchain-funcs virtualx
 
 MY_PN=Pillow
 MY_P=${MY_PN}-${PV}
@@ -47,7 +47,7 @@ DEPEND="${RDEPEND}
 S="${WORKDIR}/${MY_P}"
 
 PATCHES=(
-	"${FILESDIR}/${PN}-5.2.0-fix-lib-paths.patch"
+	"${FILESDIR}"/${PN}-5.4.1-{pkg-config,toolchain-paths}.patch
 )
 
 python_configure_all() {
@@ -66,6 +66,17 @@ python_configure_all() {
 		$(use_enable webp webpmux)
 		$(use_enable zlib)
 	)
+
+	# setup.py sucks at adding the right toolchain paths but it does
+	# accept additional ones from INCLUDE and LIB so set these. You
+	# wouldn't normally need these at all as the toolchain should look
+	# here anyway but this setup.py does stupid things.
+	export \
+		INCLUDE=${ESYSROOT}/usr/include \
+		LIB=${ESYSROOT}/usr/$(get_libdir)
+
+	# We have patched in this env var.
+	tc-export PKG_CONFIG
 }
 
 python_compile_all() {