Enable build with mpfr library.

Signed-off-by: Ray-V <ray-v@inbox.lv>
(cherry picked from commit 0c17ab1f20)

ConfigureChecks.cmake

@@ -43,5 +43,6 @@ check_type_size( "long" SIZEOF_LONG BUILTIN_TYPES_ONLY )
 check_include_file( stdint.h HAVE_STDINT_H )
 check_include_file( systems.h HAVE_SYSTEMS_H )
 check_include_file( linux/inotify.h HAVE_INOTIFY )
+check_include_file( mpfr.h HAVE_MPFR )
 
 check_function_exists( statvfs HAVE_STATVFS )

src/CMakeLists.txt

@@ -37,11 +37,11 @@ GENERATE_BISON_FLEX_SOURCES(${CMAKE_SOURCE_DIR}/src/parser.yy "" ${CMAKE_SOURCE_
 
 if( HAVE_MPFR )
   set( MPFR_SOURCES "" )
-  set( MPFR_LIBRARIES "mpfr gmp" )
-else( HAVE_MPFR )
+  set( MPFR_LIBRARIES mpfr gmp )
+else( )
   set( MPFR_SOURCES hmath.cpp number.c )
   set( MPFR_LIBRARIES "" )
-endif( HAVE_MPFR )
+endif( )
 
 tde_add_executable( abakus AUTOMOC
   SOURCES abakus.cpp abakuslistview.cpp