Random fixes. E.g., (random) never returned negative values.

* fns.c (Frandom): Use GET_EMACS_TIME for random seed, and add the
subseconds part to the entropy, as that's a bit more random.
Prefer signed to unsigned, since the signedness doesn't matter and
in general we prefer signed.  When given a limit, use a
denominator equal to INTMASK + 1, not to VALMASK + 1, because the
latter isn't right if USE_2_TAGS_FOR_INTS.
* sysdep.c (get_random): Return a value in the range 0..INTMASK,
not 0..VALMASK.  Don't discard "excess" bits that random () returns.

1 files changed, 12 insertions, 0 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 17a6179f356..9ad7da46ecf 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,15 @@
+2011-07-05  Paul Eggert  <eggert@cs.ucla.edu>
+
+        Random fixes.  E.g., (random) never returned negative values.
+        * fns.c (Frandom): Use GET_EMACS_TIME for random seed, and add the
+        subseconds part to the entropy, as that's a bit more random.
+        Prefer signed to unsigned, since the signedness doesn't matter and
+        in general we prefer signed.  When given a limit, use a
+        denominator equal to INTMASK + 1, not to VALMASK + 1, because the
+        latter isn't right if USE_2_TAGS_FOR_INTS.
+        * sysdep.c (get_random): Return a value in the range 0..INTMASK,
+        not 0..VALMASK.  Don't discard "excess" bits that random () returns.
+
 2011-07-04  Stefan Monnier  <monnier@iro.umontreal.ca>
 
         * textprop.c (text_property_stickiness):