This patch is backported from the upcoming 2.4 release. It corrects
highlighting behavior for plugins such as urlserver.py.

See-Also: https://github.com/weechat/weechat/issues/1277
Patch-Author: Sébastien Helleu <flashcode@flashtux.org>

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 0ae69ea0f..1d7738af5 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -27,8 +27,8 @@ project(weechat C)
 set(CMAKE_VERBOSE_MAKEFILE OFF)
 set(CMAKE_MODULE_PATH ${CMAKE_SOURCE_DIR}/cmake ${CMAKE_MODULE_PATH})
 set(CMAKE_SKIP_RPATH ON)
-set(CMAKE_C_FLAGS   "${CMAKE_C_FLAGS} -Wall -Wextra -Werror-implicit-function-declaration")
-set(CMAKE_CXX_FLAGS "${CMAKE_C_FLAGS} -Wall -Wextra -Werror-implicit-function-declaration")
+set(CMAKE_C_FLAGS   "${CMAKE_C_FLAGS} -fsigned-char -Wall -Wextra -Werror-implicit-function-declaration")
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fsigned-char -Wall -Wextra -Werror-implicit-function-declaration")
 
 # version
 execute_process(COMMAND ${CMAKE_SOURCE_DIR}/version.sh devel-major OUTPUT_VARIABLE VERSION_MAJOR)
diff --git a/configure.ac b/configure.ac
index d267ca10f..a0bf00078 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1330,7 +1330,7 @@ AC_DEFINE_UNQUOTED(WEECHAT_SHAREDIR, "$WEECHAT_SHAREDIR")
 weechat_libdir=${libdir}/weechat
 AC_SUBST(weechat_libdir)
 
-COMMON_CFLAGS="-Wall -Wextra -Werror-implicit-function-declaration"
+COMMON_CFLAGS="-fsigned-char -Wall -Wextra -Werror-implicit-function-declaration"
 AC_MSG_CHECKING([whether we have GNU assembler])
 GAS=`as --version < /dev/null 2>/dev/null | grep GNU`
 if test "$GAS"; then
-- 
2.19.1