Add workaround for flex-2.6.0 bug causing build failure

kf5-kservice.spec

@@ -31,6 +31,9 @@ Patch100:  kservice-5.15.0-xdg-menu.patch
 # hide that by default, make it qCDebug instead (of qCWarning)
 Patch101:  kservice-5.17.0-vfolder_spam.patch
 
+# Workaround flex bug (https://bugzilla.redhat.com/show_bug.cgi?id=1364943)
+Patch102:  kservice-5.25-fix-build-with-flex-2.6.0.patch
+
 BuildRequires:  extra-cmake-modules >= %{version}
 BuildRequires:  kf5-kconfig-devel >= %{version}
 BuildRequires:  kf5-kcoreaddons-devel >= %{version}

kservice-5.25-fix-build-with-flex-2.6.0.patch

@@ -0,0 +1,13 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 3a521c8..2c0a323 100644
+--- a/CMakeLists.txt
++++ b/CMakeLists.txt
+@@ -61,6 +61,8 @@ set_package_properties(BISON PROPERTIES
+     PURPOSE "Required for the Trader parser"
+ )
+ 
++set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=c99")
++
+ # create a Config.cmake and a ConfigVersion.cmake file and install them
+ set(CMAKECONFIG_INSTALL_DIR "${KDE_INSTALL_CMAKEPACKAGEDIR}/KF5Service")
+