PuTTY bug unix-lp64

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summary: PuTTY is broken on LP64 Unix systems
class: bug: This is clearly an actual problem we want fixed.
difficulty: fun: Just needs tuits, and not many of them.
priority: medium: This should be fixed one day.
present-in: 0.58
fixed-in: r8855 (0.61) (0.62)
From Debian bug #336390:
Symptoms:
I start pterm. It brings up its window, which is cleared to black
with the cursor in the top left corner. After this, nothing happens: the
expected shell prompt isn't printed. Pressing keys has no visible effect.
When I click the mouse on the window or use the window manager to switch
away this causes pterm to suddenly update, printing the shell prompt plus
any characters corresponding to keys I had pressed earlier (and if say
I had pressed 'ls' I also get the ls output now).
...
Actual problem:
The gtkwin.c timer code implicitly assumes sizeof(int)==sizeof(long).
On alpha, long is 64 bit, so timer ticks as returned by GETTICKCOUNT()
are 64 bits (and at time of writing well overflowing into the high
word). However, we pass this through to the timer_trigger() routine
with GINT_TO_POINTER() and then retrieve it with GPOINTER_TO_INT().
Unfortunately on alpha GPOINTER_TO_INT(x) is defined as
((gint)  (glong) (x)), which truncates the count to 32 bits.
The upshot is that the next timeout is scheduled for aeons in the
future, and we never actually draw anything.

Patch:

---begin---
--- gtkwin.c.orig       2005-10-29 22:58:37.000000000 +0100
+++ gtkwin.c    2005-10-30 00:22:57.000000000 +0100
@@ -1187,14 +1187,14 @@
 
 static gint timer_trigger(gpointer data)
 {
-    long now = GPOINTER_TO_INT(data);
+    long now = (long)(data);
     long next;
     long ticks;
 
     if (run_timers(now, &next)) {
        ticks = next - GETTICKCOUNT();
        timer_id = gtk_timeout_add(ticks > 0 ? ticks : 1, timer_trigger,
-                                  GINT_TO_POINTER(next));
+                                  (gpointer)(next));
     }
 
     /*
@@ -1216,7 +1216,7 @@
        ticks = 1;                     /* just in case */
 
     timer_id = gtk_timeout_add(ticks, timer_trigger,
-                              GINT_TO_POINTER(next));
+                              (gpointer)(next));
 }
 
 void fd_input_func(gpointer data, gint sourcefd, GdkInputCondition condition)
---endit---

Disclaimer: works for me on the Alpha, but totally untested on
32 bit machines. Almost certainly won't work on systems where
pointers are 32 bit but long is 64 bit.

I think that we only ever have one outstanding timer (since
timer_id is a single global, not an array), so we could just
keep 'next' in a global, rather than trying to stuff it into
a pointer and pull it back out again; maybe that'd be cleaner?

Or we could force timer ticks to be 32 bit integers on all
platforms...

Audit trail for this bug.


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(last revision of this bug record was at 2010-02-20 19:09:53 +0000)