Fix bug when time_t is unsigned and as wide as intmax_t.

* lisp.h (WAIT_READING_MAX): New macro.
* dispnew.c (Fsleep_for, sit_for):
* keyboard.c (kbd_buffer_get_event):
* process.c (Faccept_process_output):
Use it to avoid bogus compiler warnings with obsolescent GCC versions.
This improves on the previous patch, which introduced a bug
when time_t is unsigned and as wide as intmax_t.
See <http://bugs.gnu.org/9000#51>.

5 files changed, 25 insertions, 12 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 40073d32834..a302db4fae6 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,15 @@
+2012-06-24  Paul Eggert  <eggert@cs.ucla.edu>
+
+        Fix bug when time_t is unsigned and as wide as intmax_t (Bug#9000).
+        * lisp.h (WAIT_READING_MAX): New macro.
+        * dispnew.c (Fsleep_for, sit_for):
+        * keyboard.c (kbd_buffer_get_event):
+        * process.c (Faccept_process_output):
+        Use it to avoid bogus compiler warnings with obsolescent GCC versions.
+        This improves on the previous patch, which introduced a bug
+        when time_t is unsigned and as wide as intmax_t.
+        See <http://bugs.gnu.org/9000#51>.
+
 2012-06-23  Eli Zaretskii  <eliz@gnu.org>
 
         * dispnew.c (sit_for, Fsleep_for):
diff --git a/src/dispnew.c b/src/dispnew.c
index e18fca6f122..05c22be79ae 100644
--- a/src/dispnew.c
+++ b/src/dispnew.c
@@ -5957,9 +5957,7 @@ additional wait period, in milliseconds; this is for backwards compatibility.
   if (0 < duration)
     {
       EMACS_TIME t = EMACS_TIME_FROM_DOUBLE (duration);
-      intmax_t secs = EMACS_SECS (t);
-
-      wait_reading_process_output (min (secs, INTMAX_MAX),
+      wait_reading_process_output (min (EMACS_SECS (t), WAIT_READING_MAX),
                                    EMACS_NSECS (t), 0, 0, Qnil, NULL, 0);
     }
 
@@ -6007,8 +6005,7 @@ sit_for (Lisp_Object timeout, int reading, int do_display)
       else
         {
           EMACS_TIME t = EMACS_TIME_FROM_DOUBLE (seconds);
-          sec = EMACS_SECS (t);
-          sec = min (sec, INTMAX_MAX);
+          sec = min (EMACS_SECS (t), WAIT_READING_MAX);
           nsec = EMACS_NSECS (t);
         }
     }
diff --git a/src/keyboard.c b/src/keyboard.c
index 38b05c22063..a39be2b859c 100644
--- a/src/keyboard.c
+++ b/src/keyboard.c
@@ -3857,11 +3857,9 @@ kbd_buffer_get_event (KBOARD **kbp,
             return Qnil;        /* finished waiting */
           else
             {
-              intmax_t secs;
-
               EMACS_SUB_TIME (duration, *end_time, duration);
-              secs = EMACS_SECS (duration);
-              wait_reading_process_output (min (secs, INTMAX_MAX),
+              wait_reading_process_output (min (EMACS_SECS (duration),
+                                                WAIT_READING_MAX),
                                            EMACS_NSECS (duration),
                                            -1, 1, Qnil, NULL, 0);
             }
diff --git a/src/lisp.h b/src/lisp.h
index dd8cdd348b2..275761b0e94 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -3249,6 +3249,14 @@ extern int wait_reading_process_output (intmax_t, int, int, int,
                                         Lisp_Object,
                                         struct Lisp_Process *,
                                         int);
+/* Max value for the first argument of wait_reading_process_output.  */
+#if __GNUC__ == 3 || (__GNUC__ == 4 && __GNUC_MINOR__ <= 5)
+/* Work around a bug in GCC 3.4.2, known to be fixed in GCC 4.6.3.
+   The bug merely causes a bogus warning, but the warning is annoying.  */
+# define WAIT_READING_MAX min (TYPE_MAXIMUM (time_t), INTMAX_MAX)
+#else
+# define WAIT_READING_MAX INTMAX_MAX
+#endif
 extern void add_keyboard_wait_descriptor (int);
 extern void delete_keyboard_wait_descriptor (int);
 #ifdef HAVE_GPM
diff --git a/src/process.c b/src/process.c
index b41a77f58fd..457a1a9c7ea 100644
--- a/src/process.c
+++ b/src/process.c
@@ -3996,9 +3996,7 @@ Return non-nil if we received any output before the timeout expired.  */)
           if (0 < XFLOAT_DATA (seconds))
             {
               EMACS_TIME t = EMACS_TIME_FROM_DOUBLE (XFLOAT_DATA (seconds));
-
-              secs = EMACS_SECS (t);
-              secs = min (secs, INTMAX_MAX);
+              secs = min (EMACS_SECS (t), WAIT_READING_MAX);
               nsecs = EMACS_NSECS (t);
             }
         }