libglib2: backport upstream patch to handle missing fcntl() flags

On RHEL6 hosts, fcntl.h doesn't define F_SETPIPE_SZ or
F_GETPIPE_SZ. Upstream glib has a patch for this case that wasn't
applied to their 2.56.1 branch.

Fixes:

  http://autobuild.buildroot.net/results/04b98a0b5c593c0525ef39d03c1ee7c2bbf5e44d/

Signed-off-by: Hollis Blanchard <hollis_blanchard@mentor.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/libglib2/0005-gio-fix-compilation-without-F_-S-G-ETPIPE_SZ.patch

@@ -0,0 +1,52 @@
+From 0beb62f564072f3585762c9c55fe894485993b62 Mon Sep 17 00:00:00 2001
+From: Fabrice Fontaine <fontaine.fabrice@gmail.com>
+Date: Tue, 10 Apr 2018 18:55:11 +0200
+Subject: [PATCH] gio: fix compilation without F_{S,G}ETPIPE_SZ
+
+Commit a5778ef7c51044147fe470ea1707dd297f44f880 broke compilation on
+architectures without F_SETPIPE_SZ and F_GETPIPE_SZ such as or1k.
+If those variables are undefined, put back previous behavior, buffer
+size set to 1024 * 64
+
+Fixes:
+ - http://autobuild.buildroot.net/results/398490e07343a931b25ca6ab5c90a75d7a073e9f
+
+(Modified by Philip Withnall <withnall@endlessm.com> to add an
+explanatory comment.)
+
+Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
+
+https://bugzilla.gnome.org/show_bug.cgi?id=795133
+---
+ gio/gfile.c | 8 ++++++++
+ 1 file changed, 8 insertions(+)
+
+diff --git a/gio/gfile.c b/gio/gfile.c
+index 334ad8ec3..a67aad383 100644
+--- a/gio/gfile.c
++++ b/gio/gfile.c
+@@ -3012,6 +3012,7 @@ splice_stream_with_progress (GInputStream           *in,
+   if (!g_unix_open_pipe (buffer, FD_CLOEXEC, error))
+     return FALSE;
+ 
++#if defined(F_SETPIPE_SZ) && defined(F_GETPIPE_SZ)
+   /* Try a 1MiB buffer for improved throughput. If that fails, use the default
+    * pipe size. See: https://bugzilla.gnome.org/791457 */
+   buffer_size = fcntl (buffer[1], F_SETPIPE_SZ, 1024 * 1024);
+@@ -3029,6 +3030,13 @@ splice_stream_with_progress (GInputStream           *in,
+           goto out;
+         }
+     }
++#else
++  /* If #F_GETPIPE_SZ isn’t available, assume we’re on Linux < 2.6.35,
++   * but ≥ 2.6.11, meaning the pipe capacity is 64KiB. Ignore the possibility of
++   * running on Linux < 2.6.11 (where the capacity was the system page size,
++   * typically 4KiB) because it’s ancient. See pipe(7). */
++  buffer_size = 1024 * 64;
++#endif
+ 
+   g_assert (buffer_size > 0);
+ 
+-- 
+2.13.0
+