FW: tzcode2006a.tar.gz on Irix 6.5.18m

[Paul Eggert]

Thanks for looking into the problem.  zdump.c relies on undefined
behavior on overflow, which is the problem here, but if we can assume
C99+LIA-1 semantics (the common case) we can get a reliable result.
Also, I think it's safer to avoid 'register'.

Does the following patch to zdump.c fix things for you?

--- zdump.c	2006/02/02 20:42:22	2005.18.0.1
+++ zdump.c	2006/02/08 00:33:28
@@ -418,14 +418,21 @@ _("%s: use of -v on system with floating
 		}
 	} else if (0 > (time_t) -1) {
 		/*
-		** time_t is signed.
+		** time_t is signed.  Assume overflow wraps around.
 		*/
-		register time_t	hibit;
+		time_t t = 0;
+		time_t t1 = 1;
 
-		for (hibit = 1; (hibit * 2) != 0; hibit *= 2)
-			continue;
-		absolute_min_time = hibit;
-		absolute_max_time = -(hibit + 1);
+		while (t < t1) {
+			t = t1;
+			t1 = 2 * t1 + 1;
+		}
+		  
+		absolute_max_time = t;
+		t = -t;
+		absolute_min_time = t - 1;
+		if (t < absolute_min_time)
+			absolute_min_time = t;
 	} else {
 		/*
 		** time_t is unsigned.