Fix subsetting when lenIV = 0.  (lenIV = 0 => No padding, lenIV = -1 => No encryption.)

--- src/texk/web2c/mpdir/writet1.c.orig	2008-05-13 06:05:10.000000000 -0700
+++ src/texk/web2c/mpdir/writet1.c	2009-03-20 17:49:53.000000000 -0700
@@ -1524,7 +1524,7 @@
         cr = 4330;
         cs_len = 0;
         return_cs = xtalloc (t1_lenIV + 1, byte);
-        if (t1_lenIV > 0) {
+        if (t1_lenIV >= 0) {
             for (cs_len = 0, r = return_cs; cs_len < t1_lenIV; cs_len++, r++)
                 *r = cencrypt (0x00, &cr);
             *r = cencrypt (CS_RETURN, &cr);
--- src/texk/web2c/pdftexdir/writet1.c.orig	2008-03-31 03:07:16.000000000 -0700
+++ src/texk/web2c/pdftexdir/writet1.c	2009-03-20 17:47:11.000000000 -0700
@@ -1492,7 +1492,7 @@
         cr = 4330;
         cs_len = 0;
         return_cs = xtalloc(t1_lenIV + 1, byte);
-        if (t1_lenIV > 0) {
+        if (t1_lenIV >= 0) {
             for (cs_len = 0, r = return_cs; cs_len < t1_lenIV; cs_len++, r++)
                 *r = cencrypt(0x00, &cr);
             *r = cencrypt(CS_RETURN, &cr);