dev-libs/libffi: allow includedir= override, bug #643582

It's not a fix for bug #643582 as includes location did
not change. But a step towards it.

Changes are:
- updated to EAPI=6
- backported upstream commit
    https://github.com/libffi/libffi/commit/982b89c01aca99c7bc229914fc1521f96930919b
  ("Install public headers in the standard path")
- but overrode default location as
    --includedir=/usr/$(get_libdir)/${P}/include/
  to keep python from breaking: bug #643582#c2.

Reported-by: William L. Thomson Jr.
Bug: https://bugs.gentoo.org/643582
Package-Manager: Portage-2.3.19, Repoman-2.3.6

3 files changed, 97 insertions, 2 deletions

diff --git a/dev-libs/libffi/files/libffi-3.2.1-complex_alpha.patch b/dev-libs/libffi/files/libffi-3.2.1-complex_alpha.patch
index 0d6e0bc29007..5e8c943eee38 100644
--- a/dev-libs/libffi/files/libffi-3.2.1-complex_alpha.patch
+++ b/dev-libs/libffi/files/libffi-3.2.1-complex_alpha.patch
@@ -1,5 +1,5 @@
---- src/alpha/osf.S.orig	2015-01-16 10:46:15.000000000 +0100
-+++ src/alpha/osf.S	2015-01-16 10:46:24.000000000 +0100
+--- a/src/alpha/osf.S.orig	2015-01-16 10:46:15.000000000 +0100
++++ b/src/alpha/osf.S	2015-01-16 10:46:24.000000000 +0100
 @@ -279,6 +279,7 @@
  	.gprel32 $load_64	# FFI_TYPE_SINT64
  	.gprel32 $load_none	# FFI_TYPE_STRUCT
diff --git a/dev-libs/libffi/files/libffi-3.2.1-include-path-autogen.patch b/dev-libs/libffi/files/libffi-3.2.1-include-path-autogen.patch
new file mode 100644
index 000000000000..522e1fa9c486
--- /dev/null
+++ b/dev-libs/libffi/files/libffi-3.2.1-include-path-autogen.patch
@@ -0,0 +1,56 @@
+Autogenerated part of libffi-3.2.1-include-path.patch
+
+https://bugs.gentoo.org/643582
+diff --git a/include/Makefile.in b/include/Makefile.in
+index 9d747e8..99ecfd7 100644
+--- a/include/Makefile.in
++++ b/include/Makefile.in
+@@ -152,2 +152,2 @@ am__uninstall_files_from_dir = { \
+-am__installdirs = "$(DESTDIR)$(includesdir)"
+-HEADERS = $(nodist_includes_HEADERS)
++am__installdirs = "$(DESTDIR)$(includedir)"
++HEADERS = $(nodist_include_HEADERS)
+@@ -317,2 +317 @@ EXTRA_DIST = ffi.h.in ffi_common.h
+-includesdir = $(libdir)/@PACKAGE_NAME@-@PACKAGE_VERSION@/include
+-nodist_includes_HEADERS = ffi.h ffitarget.h
++nodist_include_HEADERS = ffi.h ffitarget.h
+@@ -360 +359 @@ clean-libtool:
+-install-nodist_includesHEADERS: $(nodist_includes_HEADERS)
++install-nodist_includeHEADERS: $(nodist_include_HEADERS)
+@@ -362 +361 @@ install-nodist_includesHEADERS: $(nodist_includes_HEADERS)
+-	@list='$(nodist_includes_HEADERS)'; test -n "$(includesdir)" || list=; \
++	@list='$(nodist_include_HEADERS)'; test -n "$(includedir)" || list=; \
+@@ -364,2 +363,2 @@ install-nodist_includesHEADERS: $(nodist_includes_HEADERS)
+-	  echo " $(MKDIR_P) '$(DESTDIR)$(includesdir)'"; \
+-	  $(MKDIR_P) "$(DESTDIR)$(includesdir)" || exit 1; \
++	  echo " $(MKDIR_P) '$(DESTDIR)$(includedir)'"; \
++	  $(MKDIR_P) "$(DESTDIR)$(includedir)" || exit 1; \
+@@ -372,2 +371,2 @@ install-nodist_includesHEADERS: $(nodist_includes_HEADERS)
+-	  echo " $(INSTALL_HEADER) $$files '$(DESTDIR)$(includesdir)'"; \
+-	  $(INSTALL_HEADER) $$files "$(DESTDIR)$(includesdir)" || exit $$?; \
++	  echo " $(INSTALL_HEADER) $$files '$(DESTDIR)$(includedir)'"; \
++	  $(INSTALL_HEADER) $$files "$(DESTDIR)$(includedir)" || exit $$?; \
+@@ -376 +375 @@ install-nodist_includesHEADERS: $(nodist_includes_HEADERS)
+-uninstall-nodist_includesHEADERS:
++uninstall-nodist_includeHEADERS:
+@@ -378 +377 @@ uninstall-nodist_includesHEADERS:
+-	@list='$(nodist_includes_HEADERS)'; test -n "$(includesdir)" || list=; \
++	@list='$(nodist_include_HEADERS)'; test -n "$(includedir)" || list=; \
+@@ -380 +379 @@ uninstall-nodist_includesHEADERS:
+-	dir='$(DESTDIR)$(includesdir)'; $(am__uninstall_files_from_dir)
++	dir='$(DESTDIR)$(includedir)'; $(am__uninstall_files_from_dir)
+@@ -468 +467 @@ installdirs:
+-	for dir in "$(DESTDIR)$(includesdir)"; do \
++	for dir in "$(DESTDIR)$(includedir)"; do \
+@@ -522 +521 @@ info-am:
+-install-data-am: install-nodist_includesHEADERS
++install-data-am: install-nodist_includeHEADERS
+@@ -566 +565 @@ ps-am:
+-uninstall-am: uninstall-nodist_includesHEADERS
++uninstall-am: uninstall-nodist_includeHEADERS
+@@ -577 +576 @@ uninstall-am: uninstall-nodist_includesHEADERS
+-	install-nodist_includesHEADERS install-pdf install-pdf-am \
++	install-nodist_includeHEADERS install-pdf install-pdf-am \
+@@ -582 +581 @@ uninstall-am: uninstall-nodist_includesHEADERS
+-	uninstall-am uninstall-nodist_includesHEADERS
++	uninstall-am uninstall-nodist_includeHEADERS
diff --git a/dev-libs/libffi/files/libffi-3.2.1-include-path.patch b/dev-libs/libffi/files/libffi-3.2.1-include-path.patch
new file mode 100644
index 000000000000..e1269b2398a4
--- /dev/null
+++ b/dev-libs/libffi/files/libffi-3.2.1-include-path.patch
@@ -0,0 +1,39 @@
+https://bugs.gentoo.org/643582
+
+From 982b89c01aca99c7bc229914fc1521f96930919b Mon Sep 17 00:00:00 2001
+From: Yen Chi Hsuan <yan12125@gmail.com>
+Date: Sun, 13 Nov 2016 19:17:19 +0800
+Subject: [PATCH] Install public headers in the standard path
+
+---
+ include/Makefile.am | 3 +--
+ libffi.pc.in        | 2 +-
+ 2 files changed, 2 insertions(+), 3 deletions(-)
+
+diff --git a/include/Makefile.am b/include/Makefile.am
+index bb241e8..c59df9f 100644
+--- a/include/Makefile.am
++++ b/include/Makefile.am
+@@ -6,5 +6,4 @@ DISTCLEANFILES=ffitarget.h
+ noinst_HEADERS=ffi_common.h ffi_cfi.h
+ EXTRA_DIST=ffi.h.in
+ 
+-includesdir = $(libdir)/@PACKAGE_NAME@-@PACKAGE_VERSION@/include
+-nodist_includes_HEADERS = ffi.h ffitarget.h
++nodist_include_HEADERS = ffi.h ffitarget.h
+diff --git a/libffi.pc.in b/libffi.pc.in
+index edf6fde..6fad83b 100644
+--- a/libffi.pc.in
++++ b/libffi.pc.in
+@@ -2,7 +2,7 @@ prefix=@prefix@
+ exec_prefix=@exec_prefix@
+ libdir=@libdir@
+ toolexeclibdir=@toolexeclibdir@
+-includedir=${libdir}/@PACKAGE_NAME@-@PACKAGE_VERSION@/include
++includedir=@includedir@
+ 
+ Name: @PACKAGE_NAME@
+ Description: Library supporting Foreign Function Interfaces
+-- 
+2.15.1
+