[src/{fits_intmax.c,fits_s.h,fits_u.h}] Fixed mpfr_fits_* functions: the

flags could be modified, and an assertion failure could be triggered in
debug mode (additional assertion checking) for non-integer numbers just
above the positive limit.
[tests/tfits.c] Many new tests.
(merged changesets r9650,9653-9655,10030-10034 from the trunk, with
mpfr_flags_t replaced by unsigned int)

git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/branches/3.1@10035 280ebfd0-de03-0410-8827-d642c229c3f4

1 files changed, 9 insertions, 1 deletions

diff --git a/src/fits_intmax.c b/src/fits_intmax.c
index f7276fada..b3ad9f182 100644
--- a/src/fits_intmax.c
+++ b/src/fits_intmax.c
@@ -33,6 +33,7 @@ http://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc.,
 int
 mpfr_fits_intmax_p (mpfr_srcptr f, mpfr_rnd_t rnd)
 {
+  unsigned int saved_flags;
   mpfr_exp_t e;
   int prec;
   mpfr_t x, y;
@@ -85,6 +86,7 @@ mpfr_fits_intmax_p (mpfr_srcptr f, mpfr_rnd_t rnd)
   MPFR_ASSERTD (e == prec);
 
   /* hard case: first round to prec bits, then check */
+  saved_flags = __gmpfr_flags;
   mpfr_init2 (x, prec);
   mpfr_set (x, f, rnd);
 
@@ -97,10 +99,16 @@ mpfr_fits_intmax_p (mpfr_srcptr f, mpfr_rnd_t rnd)
     }
   else
     {
-      res = MPFR_GET_EXP (x) == e;
+      /* Warning! Due to the rounding, x can be an infinity. Here we use
+         the fact that singular numbers have a special exponent field,
+         thus well-defined and different from e, in which case this means
+         that the number does not fit. That's why we use MPFR_EXP, not
+         MPFR_GET_EXP. */
+      res = MPFR_EXP (x) == e;
     }
 
   mpfr_clear (x);
+  __gmpfr_flags = saved_flags;
   return res;
 }