libclaw: add another patch from upstream.

dev-libs/libclaw/libclaw-1.7.4.recipe

@@ -18,7 +18,7 @@ Claw stands for \"C++ Library Absolutely Wonderful\"."
 HOMEPAGE="http://libclaw.sourceforge.net/"
 COPYRIGHT="2008-2014 Julien Jorge"
 LICENSE="GNU LGPL v2.1"
-REVISION="3"
+REVISION="4"
 SOURCE_URI="http://sourceforge.net/projects/libclaw/files/libclaw/$portVersion/libclaw-$portVersion.tar.gz"
 CHECKSUM_SHA256="0be289da7f43b1892575f14b27860af5d1e1f6961eae11653d64e625fd7924b7"
 PATCHES="libclaw-$portVersion.patchset"

dev-libs/libclaw/patches/libclaw-1.7.4.patchset

@@ -185,3 +185,26 @@ index 9e6f14a..3c3c8f3 100644
 -- 
 2.17.1
 
+From e00d4b68ebfcd1b0f1e4c4653b3d29f579027f8e Mon Sep 17 00:00:00 2001
+From: Julien Jorge <julien.jorge@stuff-o-matic.com>
+Date: Wed, 7 Dec 2016 21:36:12 +0100
+Subject: [PATCH] Use explicit bool constructor to test an istream in
+ configuration_file.
+
+---
+ claw/code/configuration_file.cpp | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/claw/code/configuration_file.cpp b/claw/code/configuration_file.cpp
+index e7bb26a..47de5e3 100644
+--- a/claw/code/configuration_file.cpp
++++ b/claw/code/configuration_file.cpp
+@@ -441,7 +441,7 @@ claw::configuration_file::file_end() const
+ bool claw::configuration_file::get_line
+ ( std::istream& is, const syntax_description& syntax, std::string& line ) const
+ {
+-  bool result = text::getline(is, line);
++  const bool result( text::getline(is, line) );
+ 
+   if ( result )
+     {