package/mpd: add choice between version 0.19 and 0.20

MPD version 0.20 being affected by GCC PR libstdc++/64735 means no mpd package
available in Buildroot for the architectures NIOSII, ARMv4, ARMv5 and SPARCv8
until GCC 7 is released.

As the next Buildroot release is in 2017.02, which is before GCC 7 is expected
to be finished we add hidden config symbols to select the version branch to use.

Note, that we bumped the version from 0.19 to 0.20 quite recently within the
current Buildroot release cycle. This way we can keep the support for mpd on
the affected architectures, like ARMv5, until GCC 7 is out.

Note, that for the version 0.19 MPD requires libglib2.

Signed-off-by: Jörg Krause <joerg.krause@embedded.rocks>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/mpd/Config.in

@@ -4,9 +4,10 @@ menuconfig BR2_PACKAGE_MPD
 	depends on BR2_USE_WCHAR # flac
 	depends on BR2_TOOLCHAIN_HAS_THREADS
 	depends on BR2_USE_MMU # fork
-	depends on BR2_TOOLCHAIN_GCC_AT_LEAST_4_9 # C++14
-	depends on !BR2_TOOLCHAIN_HAS_GCC_BUG_64735
 	depends on BR2_TOOLCHAIN_HAS_ATOMIC
+	# 0.19.x could be built with GCC 4.6, but for simplicity we require
+	# the same toolchain dependencies for all versions.
+	depends on BR2_TOOLCHAIN_GCC_AT_LEAST_4_9 # C++14
 	select BR2_PACKAGE_BOOST
 	select BR2_PACKAGE_LIBICONV if !BR2_ENABLE_LOCALE
 	select BR2_PACKAGE_MPD_TREMOR if !(BR2_PACKAGE_MPD_MAD || BR2_PACKAGE_MPD_MPG123 || BR2_PACKAGE_MPD_VORBIS || BR2_PACKAGE_MPD_WAVPACK || BR2_PACKAGE_MPD_FLAC || BR2_PACKAGE_MPD_MUSEPACK || BR2_PACKAGE_MPD_FFMPEG)
@@ -20,6 +21,24 @@ menuconfig BR2_PACKAGE_MPD
 
 if BR2_PACKAGE_MPD
 
+# Hidden config symbols to select the branch 0.20 by default and fallback
+# to branch 0.19 for toolchains affected by GCC bug PR 64735. This way we
+# keep support for mpd on some architectures, like ARMv5, until GCC 7 is
+# released, which will fix this issue.
+config BR2_PACKAGE_MPD_VERSION_STRING
+	string
+	default "0.20" if !BR2_TOOLCHAIN_HAS_GCC_BUG_64735
+	default "0.19"
+
+config BR2_PACKAGE_MPD_VERSION_0_20
+	bool
+	default y if BR2_PACKAGE_MPD_VERSION_STRING = "0.20"
+
+config BR2_PACKAGE_MPD_VERSION_0_19
+	bool
+	default y if BR2_PACKAGE_MPD_VERSION_STRING = "0.19"
+	select BR2_PACKAGE_LIBGLIB2
+
 comment "Archive plugins"
 
 config BR2_PACKAGE_MPD_BZIP2
@@ -320,6 +339,3 @@ comment "mpd needs a toolchain w/ C++, threads, wchar, gcc >= 4.9"
 	depends on BR2_TOOLCHAIN_HAS_ATOMIC
 	depends on !BR2_INSTALL_LIBSTDCPP || !BR2_USE_WCHAR || \
 		!BR2_TOOLCHAIN_HAS_THREADS || !BR2_TOOLCHAIN_GCC_AT_LEAST_4_9
-
-comment "mpd needs a toolchain not affected by GCC bug 64735"
-	depends on BR2_TOOLCHAIN_HAS_GCC_BUG_64735

package/mpd/mpd.hash

@@ -1,2 +1,3 @@
 # Locally calculated after checking pgp signature
 sha256  712b25351c12616630c580204e1c3dcba3ae2993a56cff1c346c87e334d69728  mpd-0.20.4.tar.xz
+sha256  8305b8bc026f4b6bde28b8dd09bfdddbe5590acf36358eed4d083a396e301730  mpd-0.19.21.tar.xz

package/mpd/mpd.mk

@@ -4,8 +4,12 @@
 #
 ################################################################################
 
-MPD_VERSION_MAJOR = 0.20
+MPD_VERSION_MAJOR = $(call qstrip,$(BR2_PACKAGE_MPD_VERSION_STRING))
+ifeq ($(BR2_PACKAGE_MPD_VERSION_0_20),y)
 MPD_VERSION = $(MPD_VERSION_MAJOR).4
+else
+MPD_VERSION = $(MPD_VERSION_MAJOR).21
+endif
 MPD_SOURCE = mpd-$(MPD_VERSION).tar.xz
 MPD_SITE = http://www.musicpd.org/download/mpd/$(MPD_VERSION_MAJOR)
 MPD_DEPENDENCIES = host-pkgconf boost
@@ -13,6 +17,10 @@ MPD_LICENSE = GPLv2+
 MPD_LICENSE_FILES = COPYING
 MPD_AUTORECONF = YES
 
+ifeq ($(BR2_MPD_VERSION_0_19),y)
+MPD_DEPENDENCIES += libglib2
+endif
+
 # Some options need an explicit --disable or --enable
 
 # Zeroconf support depends on libdns_sd from avahi.