Fix (round 1e+INF) core dump

* src/bignum.c (double_to_integer): Signal an error
if D cannot be converted, instead of dumping core.
* test/src/floatfns-tests.el (special-round): New test.

1 files changed, 5 insertions, 1 deletions

diff --git a/src/bignum.c b/src/bignum.c
index 2da2c961c47..5e86c404b70 100644
--- a/src/bignum.c
+++ b/src/bignum.c
@@ -23,6 +23,7 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 
 #include "lisp.h"
 
+#include <math.h>
 #include <stdlib.h>
 
 /* mpz global temporaries.  Making them global saves the trouble of
@@ -64,10 +65,13 @@ bignum_to_double (Lisp_Object n)
   return mpz_get_d (XBIGNUM (n)->value);
 }
 
-/* Return D, converted to a Lisp integer.  Discard any fraction.  */
+/* Return D, converted to a Lisp integer.  Discard any fraction.
+   Signal an error if D cannot be converted.  */
 Lisp_Object
 double_to_integer (double d)
 {
+  if (!isfinite (d))
+    overflow_error ();
   mpz_set_d (mpz[0], d);
   return make_integer_mpz ();
 }