added limboverflow.patch, rhbz#1171701, rhbz#1171710, there was one less limb allocated in strtofr

limboverflow.patch

@@ -0,0 +1,15 @@
+--- mpfr-3.1.2-a/src/strtofr.c	2013-03-13 15:37:32.000000000 +0000
++++ mpfr-3.1.2-b/src/strtofr.c	2014-12-04 01:41:57.287791246 +0000
+@@ -473,8 +473,10 @@
+       /* prec bits corresponds to ysize limbs */
+       ysize_bits = ysize * GMP_NUMB_BITS;
+       /* and to ysize_bits >= prec > MPFR_PREC (x) bits */
+-      y = MPFR_TMP_LIMBS_ALLOC (2 * ysize + 1);
+-      y += ysize; /* y has (ysize+1) allocated limbs */
++      /* we need to allocate one more limb to work around bug
++         https://gmplib.org/list-archives/gmp-bugs/2013-December/003267.html */
++      y = MPFR_TMP_LIMBS_ALLOC (2 * ysize + 2);
++      y += ysize; /* y has (ysize+2) allocated limbs */
+ 
+       /* pstr_size is the number of characters we read in pstr->mant
+          to have at least ysize full limbs.

mpfr.spec

@@ -1,7 +1,7 @@
 Summary: A C library for multiple-precision floating-point computations
 Name: mpfr
 Version: 3.1.2
-Release: 4%{?dist}
+Release: 5%{?dist}
 URL: http://www.mpfr.org/
 Source0: http://www.mpfr.org/mpfr-current/%{name}-%{version}.tar.xz
 # GFDL  (mpfr.texi, mpfr.info and fdl.texi)
@@ -84,6 +84,9 @@ fi
 %{_infodir}/mpfr.info*
 
 %changelog
+* Fri Dec 12 2014 Frantisek Kluknavsky <fkluknav@redhat.com> - 3.1.2-5
+- added limboverflow.patch, rhbz#1171701, rhbz#1171710, there was one less limb allocated in strtofr
+
 * Tue Aug 06 2013 Ralf Corsépius <corsepiu@fedoraproject.org> - 3.1.2-4
 - Install docs into unversioned docdir (Fix FTBFS RHBZ#992296).
 - Append --disable-static to %%configure.