From c11cebc4d3ddc1ac2bf8ed3645f90faa8047e234 Mon Sep 17 00:00:00 2001
From: nicoo <nicoo@debian.org>
Date: Wed, 19 Aug 2020 10:21:32 +0200
Subject: [PATCH 1/3] factor::numeric::gcd: Exclude the 0 case from test
 `divisor`

---
 src/uu/factor/src/numeric/gcd.rs | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/uu/factor/src/numeric/gcd.rs b/src/uu/factor/src/numeric/gcd.rs
index 6273e788c..ee5b165f3 100644
--- a/src/uu/factor/src/numeric/gcd.rs
+++ b/src/uu/factor/src/numeric/gcd.rs
@@ -75,8 +75,7 @@ mod tests {
         fn divisor(a: u64, b: u64) -> bool {
             // Test that gcd(a, b) divides a and b
             let g = gcd(a, b);
-            if g == 0 { return a == 0 && b == 0; }
-            a % g == 0 && b % g == 0
+            (a == 0 && b == 0) || (a % g == 0 && b % g == 0)
         }
 
         fn commutative(a: u64, b: u64) -> bool {

From 07eaa7fe5a23e49f55c656a89959be23af779a32 Mon Sep 17 00:00:00 2001
From: nicoo <nicoo@debian.org>
Date: Wed, 19 Aug 2020 10:25:39 +0200
Subject: [PATCH 2/3] factor::numeric::gcd: Add explicit test for the 0 case

---
 src/uu/factor/src/numeric/gcd.rs | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/uu/factor/src/numeric/gcd.rs b/src/uu/factor/src/numeric/gcd.rs
index ee5b165f3..f5b66a937 100644
--- a/src/uu/factor/src/numeric/gcd.rs
+++ b/src/uu/factor/src/numeric/gcd.rs
@@ -72,6 +72,10 @@ mod tests {
             gcd(1, a) == 1
         }
 
+        fn zero(a: u64) -> bool {
+            gcd(0, a) == a
+        }
+
         fn divisor(a: u64, b: u64) -> bool {
             // Test that gcd(a, b) divides a and b
             let g = gcd(a, b);

From c33284f38b9d40bd3d08ffebecb7d452bf8e03f4 Mon Sep 17 00:00:00 2001
From: Roy Ivy III <rivy.dev@gmail.com>
Date: Thu, 3 Sep 2020 14:47:36 -0500
Subject: [PATCH 3/3] factor::numeric::gcd: modify `divisor()` test to return
 correct true/false results for all possible inputs

---
 src/uu/factor/src/numeric/gcd.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/uu/factor/src/numeric/gcd.rs b/src/uu/factor/src/numeric/gcd.rs
index f5b66a937..01e4a23bd 100644
--- a/src/uu/factor/src/numeric/gcd.rs
+++ b/src/uu/factor/src/numeric/gcd.rs
@@ -79,7 +79,7 @@ mod tests {
         fn divisor(a: u64, b: u64) -> bool {
             // Test that gcd(a, b) divides a and b
             let g = gcd(a, b);
-            (a == 0 && b == 0) || (a % g == 0 && b % g == 0)
+            (g != 0 && a % g == 0 && b % g == 0) || (g == 0 && a == 0 && b == 0)
         }
 
         fn commutative(a: u64, b: u64) -> bool {