add giflib port

ports/giflib/CMakeLists.txt

@@ -0,0 +1,33 @@
+cmake_minimum_required(VERSION 3.4)
+
+project(giflib)
+
+set(GIFLIB_HEADERS
+    lib/gif_lib.h
+)
+
+set(GIFLIB_SOURCES
+    lib/dgif_lib.c
+    lib/egif_lib.c
+    lib/gif_err.c
+    lib/gif_font.c
+    lib/gif_hash.c
+    lib/gifalloc.c
+    lib/openbsd-reallocarray.c
+    lib/quantize.c
+)
+
+add_library(gif ${GIFLIB_SOURCES})
+if (BUILD_SHARED_LIBS)
+    set_property(TARGET gif PROPERTY WINDOWS_EXPORT_ALL_SYMBOLS ON)
+endif ()
+
+if (NOT GIFLIB_SKIP_HEADERS)
+    install(FILES ${GIFLIB_HEADERS} DESTINATION include)
+endif ()
+
+install(TARGETS gif
+    RUNTIME DESTINATION bin
+    LIBRARY DESTINATION lib
+    ARCHIVE DESTINATION lib
+)

ports/giflib/CONTROL

@@ -0,0 +1,3 @@
+Source: giflib
+Version: 5.1.4
+Description: A library for reading and writing gif images.

ports/giflib/msvc-guard-unistd-h.patch

@@ -0,0 +1,52 @@
+diff -Naur a/lib/dgif_lib.c b/lib/dgif_lib.c
+--- a/lib/dgif_lib.c	2016-04-02 21:34:00.000000000 +0600
++++ b/lib/dgif_lib.c	2017-04-21 07:06:48.781271400 +0700
+@@ -12,7 +12,9 @@
+ #include <limits.h>
+ #include <stdint.h>
+ #include <fcntl.h>
++#ifndef _MSC_VER
+ #include <unistd.h>
++#endif
+ #include <stdio.h>
+ #include <string.h>
+ 
+diff -Naur a/lib/egif_lib.c b/lib/egif_lib.c
+--- a/lib/egif_lib.c	2016-01-22 16:36:36.000000000 +0600
++++ b/lib/egif_lib.c	2017-04-21 07:07:08.728159900 +0700
+@@ -8,7 +8,9 @@
+ 
+ *****************************************************************************/
+ 
++#ifndef _MSC_VER
+ #include <unistd.h>
++#endif
+ #include <stdint.h>
+ #include <stdlib.h>
+ #include <stdio.h>
+diff -Naur a/lib/gif_hash.c b/lib/gif_hash.c
+--- a/lib/gif_hash.c	2014-05-16 17:46:53.000000000 +0700
++++ b/lib/gif_hash.c	2017-04-21 07:07:17.718719500 +0700
+@@ -11,7 +11,9 @@
+ 
+ *****************************************************************************/
+ 
++#ifndef _MSC_VER
+ #include <unistd.h>
++#endif
+ #include <stdint.h>
+ #include <stdlib.h>
+ #include <fcntl.h>
+diff -Naur a/lib/gif_hash.h b/lib/gif_hash.h
+--- a/lib/gif_hash.h	2014-05-16 17:46:53.000000000 +0700
++++ b/lib/gif_hash.h	2017-04-21 07:07:32.316346800 +0700
+@@ -7,7 +7,9 @@
+ #ifndef _GIF_HASH_H_
+ #define _GIF_HASH_H_
+ 
++#ifndef _MSC_VER
+ #include <unistd.h>
++#endif
+ #include <stdint.h>
+ 
+ #define HT_SIZE			8192	   /* 12bits = 4096 or twice as big! */

ports/giflib/portfile.cmake

@@ -0,0 +1,26 @@
+include(vcpkg_common_functions)
+set(SOURCE_PATH ${CURRENT_BUILDTREES_DIR}/src/giflib-5.1.4)
+vcpkg_download_distfile(ARCHIVE
+    URLS "http://downloads.sourceforge.net/sourceforge/giflib/giflib-5.1.4.tar.bz2"
+    FILENAME "giflib-5.1.4.tar.bz2"
+    SHA512 32b5e342056c210e6478e9cb3b6ceec9594dcfaf34feea1eb4dad633a081ed4465bceee578c19165907cb47cb83912ac359ceea666a8e07dbbb5420f9928f96d
+)
+vcpkg_extract_source_archive(${ARCHIVE})
+file(COPY ${CMAKE_CURRENT_LIST_DIR}/CMakeLists.txt DESTINATION ${SOURCE_PATH})
+
+vcpkg_apply_patches(
+    SOURCE_PATH ${SOURCE_PATH}
+    PATCHES
+        ${CMAKE_CURRENT_LIST_DIR}/msvc-guard-unistd-h.patch
+)
+
+vcpkg_configure_cmake(
+    SOURCE_PATH ${SOURCE_PATH}
+    OPTIONS_DEBUG
+        -DGIFLIB_SKIP_HEADERS=ON
+)
+
+vcpkg_install_cmake()
+vcpkg_copy_pdbs()
+
+file(INSTALL ${SOURCE_PATH}/COPYING DESTINATION ${CURRENT_PACKAGES_DIR}/share/giflib RENAME copyright)