# Original patch for libmpfr 3.1.2 is here:

# http://www.mpfr.org/mpfr-3.1.2/patch11

# Backported to libmpfr 2.4.2.

--- strtofr.c 2009-11-29 18:43:08.000000000 -0800

+++ strtofr.c 2015-01-23 11:30:29.242406530 -0800

@@ -464,8 +464,10 @@

/* prec bits corresponds to ysize limbs */

ysize_bits = ysize * BITS_PER_MP_LIMB;

/* and to ysize_bits >= prec > MPFR_PREC (x) bits */

- y = (mp_limb_t*) MPFR_TMP_ALLOC ((2 * ysize + 1) * sizeof (mp_limb_t));

- y += ysize; /* y has (ysize+1) allocated limbs */

+ /* we need to allocate one more limb to work around

+ * https://gmplib.org/list-archives/gmp-bugs/2013-December/003267.html */

+ y = (mp_limb_t*) MPFR_TMP_ALLOC ((2 * ysize + 2) * sizeof (mp_limb_t));

+ 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.