Fix bugs when rounding to bignums

Also, since Emacs historically reported a range error when
rounding operations overflowed, do that consistently for all
bignum overflows.
* doc/lispref/errors.texi (Standard Errors):
* doc/lispref/numbers.texi (Integer Basics): Document range errors.
* src/alloc.c (range_error): Rename from integer_overflow.
All uses changed.
* src/floatfns.c (rounding_driver): When the result of a floating
point rounding operation does not fit into a fixnum, put it
into a bignum instead of always signaling an range error.
* test/src/floatfns-tests.el (divide-extreme-sign):
These tests now return the mathematically-correct answer
instead of signaling an error.
(bignum-round): Check that integers round to themselves.

1 files changed, 3 insertions, 3 deletions

diff --git a/src/alloc.c b/src/alloc.c
index 24a24aab96b..cdcd465ac5a 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -3771,7 +3771,7 @@ make_number (mpz_t value)
   /* The documentation says integer-width should be nonnegative, so
      a single comparison suffices even though 'bits' is unsigned.  */
   if (integer_width < bits)
-    integer_overflow ();
+    range_error ();
 
   struct Lisp_Bignum *b = ALLOCATE_PSEUDOVECTOR (struct Lisp_Bignum, value,
                                                  PVEC_BIGNUM);
@@ -7203,9 +7203,9 @@ verify_alloca (void)
 /* Memory allocation for GMP.  */
 
 void
-integer_overflow (void)
+range_error (void)
 {
-  error ("Integer too large to be represented");
+  xsignal0 (Qrange_error);
 }
 
 static void *