Lisp reader now checks for integer overflow

* doc/lispref/numbers.texi (Integer Basics), etc/NEWS:
Document this.
* src/lisp.h (S2N_IGNORE_TRAILING, S2N_OVERFLOW_TO_FLOAT):
New constants.
* src/lread.c (string_to_number): Change trailing bool arg to
integer argument with flags, to support S2N_OVERFLOW_TO_FLOAT.
All uses changed.
* test/src/editfns-tests.el (read-large-integer): New test.

1 files changed, 18 insertions, 4 deletions

diff --git a/test/src/editfns-tests.el b/test/src/editfns-tests.el
index 6e1f730166d..442ad089375 100644
--- a/test/src/editfns-tests.el
+++ b/test/src/editfns-tests.el
@@ -142,27 +142,41 @@
   (should (string-equal (format "%#05X" #x10) "0X010"))
   (should (string-equal (format "%#04x" 0) "0000")))
 
-;;; Test Bug#30408.
+
+;;; Tests for Bug#30408.
+
 (ert-deftest format-%d-large-float ()
   (should (string-equal (format "%d" 18446744073709551616.0)
                         "18446744073709551616"))
   (should (string-equal (format "%d" -18446744073709551616.0)
                         "-18446744073709551616")))
 
-;;; Another test for Bug#30408.
 ;;; Perhaps Emacs will be improved someday to return the correct
 ;;; answer for positive numbers instead of overflowing; in
-;;; that case this test will need to be changed.  In the meantime make
+;;; that case these tests will need to be changed.  In the meantime make
 ;;; sure Emacs is reporting the overflow correctly.
 (ert-deftest format-%x-large-float ()
   (should-error (format "%x" 18446744073709551616.0)
                 :type 'overflow-error))
+(ert-deftest read-large-integer ()
+  (should-error (read (format "%d0" most-negative-fixnum))
+                :type 'overflow-error)
+  (should-error (read (format "%+d" (* -8.0 most-negative-fixnum)))
+                :type 'overflow-error)
+  (should-error (read (substring (format "%d" most-negative-fixnum) 1))
+                :type 'overflow-error)
+  (should-error (read (format "#x%x" most-negative-fixnum))
+                :type 'overflow-error)
+  (should-error (read (format "#o%o" most-negative-fixnum))
+                :type 'overflow-error)
+  (should-error (read (format "#32rG%x" most-positive-fixnum))
+                :type 'overflow-error))
 
-;;; Another test for Bug#30408.
 (ert-deftest format-%o-invalid-float ()
   (should-error (format "%o" -1e-37)
                 :type 'overflow-error))
 
+
 ;;; Check format-time-string with various TZ settings.
 ;;; Use only POSIX-compatible TZ values, since the tests should work
 ;;; even if tzdb is not in use.