From b34084640b6d4760a2c53dc714f82547985b7622 Mon Sep 17 00:00:00 2001
From: Matthew Flatt <mflatt@racket-lang.org>
Date: Mon, 7 Oct 2019 20:08:41 -0600
Subject: [PATCH] `pseudo-random-generator-seed!` should allow 0

original commit: 1802cca10ec6abfe4bc177a4d4d9fa0d9a201517
---
 csug/numeric.stex                | 2 +-
 mats/5_3.ms                      | 1 -
 mats/root-experr-compile-0-f-f-f | 5 ++---
 s/5_3.ss                         | 4 ++--
 4 files changed, 5 insertions(+), 7 deletions(-)

diff --git a/csug/numeric.stex b/csug/numeric.stex
index a49531824d..a468ce0461 100644
--- a/csug/numeric.stex
+++ b/csug/numeric.stex
@@ -1473,7 +1473,7 @@ and \scheme{below-int} (exclusive).
 
 \noindent
 \var{prgen} must be a psuedo-random generator state, and \var{seed-int} must
-be a positive, exact integer.
+be a nonnegative, exact integer.
 
 Sets the state of a pseduo-random generator using only 31 or so bits
 of \var{seed-int}. This procedure is useful for initializing the state
diff --git a/mats/5_3.ms b/mats/5_3.ms
index f01c883559..096715ccb7 100644
--- a/mats/5_3.ms
+++ b/mats/5_3.ms
@@ -2584,7 +2584,6 @@
     (error? (pseudo-random-generator-seed! 10 10))
     (error? (pseudo-random-generator-seed! (vector 1 2 3) 10))
     (error? (pseudo-random-generator-seed! (make-pseudo-random-generator) 10.0))
-    (error? (pseudo-random-generator-seed! (make-pseudo-random-generator) 0))
     (error? (pseudo-random-generator-seed! (make-pseudo-random-generator) -1))
 
     (error? (pseudo-random-generator->vector 0))
diff --git a/mats/root-experr-compile-0-f-f-f b/mats/root-experr-compile-0-f-f-f
index 867d500c89..b38e4e7243 100644
--- a/mats/root-experr-compile-0-f-f-f
+++ b/mats/root-experr-compile-0-f-f-f
@@ -1317,9 +1317,8 @@ primvars.mo:Expected error in mat trace-output-port: "trace-output-port: #<input
 5_3.mo:Expected error in mat pseudo-random-generator: "pseudo-random-generator-next!: not a positive exact integer 10.0".
 5_3.mo:Expected error in mat pseudo-random-generator: "pseudo-random-generator-seed!: not a pseudo-random generator 10".
 5_3.mo:Expected error in mat pseudo-random-generator: "pseudo-random-generator-seed!: not a pseudo-random generator #(1 2 3)".
-5_3.mo:Expected error in mat pseudo-random-generator: "pseudo-random-generator-seed!: not a positive exact integer 10.0".
-5_3.mo:Expected error in mat pseudo-random-generator: "pseudo-random-generator-seed!: not a positive exact integer 0".
-5_3.mo:Expected error in mat pseudo-random-generator: "pseudo-random-generator-seed!: not a positive exact integer -1".
+5_3.mo:Expected error in mat pseudo-random-generator: "pseudo-random-generator-seed!: not a nonnegative exact integer 10.0".
+5_3.mo:Expected error in mat pseudo-random-generator: "pseudo-random-generator-seed!: not a nonnegative exact integer -1".
 5_3.mo:Expected error in mat pseudo-random-generator: "pseudo-random-generator->vector: not a pseudo-random generator 0".
 5_3.mo:Expected error in mat pseudo-random-generator: "vector->pseudo-random-generator: not a valid pseudo-random generator state vector 0".
 5_3.mo:Expected error in mat pseudo-random-generator: "vector->pseudo-random-generator: not a valid pseudo-random generator state vector #(1 2 3 4 5)".
diff --git a/s/5_3.ss b/s/5_3.ss
index df8109b3aa..0473addb0d 100644
--- a/s/5_3.ss
+++ b/s/5_3.ss
@@ -2623,9 +2623,9 @@
     (set-who! pseudo-random-generator-seed!
       (lambda (s n)
         (unless (is-pseudo-random-generator? s) ($oops who "not a pseudo-random generator ~s" s))
-        (unless (or (and (fixnum? n) (fxpositive? n))
+        (unless (or (and (fixnum? n) (fx>= n 0))
                     (and (bignum? n)  ($bigpositive? n)))
-          ($oops who "not a positive exact integer ~s" n))
+          ($oops who "not a nonnegative exact integer ~s" n))
         (init! s (bitwise-and n #xFFFFFFFF)))))
 
   (set-who! pseudo-random-generator-next!