Avoid signed integer overflow when converting Time to ptrdiff_t.

* keyboard.c (INPUT_EVENT_POS_MAX, INPUT_EVENT_POS_MIN):
New macros.
(position_to_Time, Time_to_position): New functions.
(gen_help_event, kbd_buffer_get_event): Use them.
* systime.h (Time) [emacs && !HAVE_X_WINDOWS]:
Go back to plain 'unsigned long', so that 'Time' is the same
for both X and non-X builds; this is less likely to cause surprise.
* termhooks.h: Remove compile-time check that Time and ptrdiff_t
are the same size; this is no longer required.

1 files changed, 11 insertions, 0 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 9ee4a3de1d0..5f95c1594ef 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,5 +1,16 @@
 2014-09-24  Paul Eggert  <eggert@cs.ucla.edu>
 
+        Avoid signed integer overflow when converting Time to ptrdiff_t.
+        * keyboard.c (INPUT_EVENT_POS_MAX, INPUT_EVENT_POS_MIN):
+        New macros.
+        (position_to_Time, Time_to_position): New functions.
+        (gen_help_event, kbd_buffer_get_event): Use them.
+        * systime.h (Time) [emacs && !HAVE_X_WINDOWS]:
+        Go back to plain 'unsigned long', so that 'Time' is the same
+        for both X and non-X builds; this is less likely to cause surprise.
+        * termhooks.h: Remove compile-time check that Time and ptrdiff_t
+        are the same size; this is no longer required.
+
         * keyboard.c (make_lispy_event): Avoid unnecessary tests
         of bit 28 and of whether an unsigned value is negative.
         This simplifies the code a bit, and pacifies clang 3.4.