From c7b7d5f50feb290eadac5ec8e7c9d8a786b657d2 Mon Sep 17 00:00:00 2001
From: Delyan Angelov <delian66@gmail.com>
Date: Mon, 4 Dec 2023 15:21:01 +0200
Subject: [PATCH] arrays: fix off by one error in arrays.uniq_only_repeated/1
 and arrays.uniq_all_repeated/1

---
 vlib/arrays/uniq.v      |  4 ++--
 vlib/arrays/uniq_test.v | 11 +++++++++--
 2 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/vlib/arrays/uniq.v b/vlib/arrays/uniq.v
index 0b70e38a50d25f..6d41603bf4f8ad 100644
--- a/vlib/arrays/uniq.v
+++ b/vlib/arrays/uniq.v
@@ -91,7 +91,7 @@ pub fn uniq_only_repeated[T](a []T) []T {
 					// found the right border of the repeated elements
 					if j - i > 1 {
 						res << a[i]
-						i = j
+						i = j - 1
 						continue loop
 					}
 				}
@@ -132,7 +132,7 @@ pub fn uniq_all_repeated[T](a []T) []T {
 			for j := i + 1; j < a.len; j++ {
 				if a[i] != a[j] && j - i > 0 {
 					// found the right border of the repeated elements
-					i = j
+					i = j - 1
 					continue loop
 				}
 				res << a[i]
diff --git a/vlib/arrays/uniq_test.v b/vlib/arrays/uniq_test.v
index 49b20847423fa5..cc07492a6b119d 100644
--- a/vlib/arrays/uniq_test.v
+++ b/vlib/arrays/uniq_test.v
@@ -4,6 +4,8 @@ const a = [1, 5, 5, 1, 5, 2, 1, 1, 9, 2]
 
 const s = [1, 1, 1, 1, 2, 2, 5, 5, 5, 9] // a.sorted()
 
+const many_repeats = [1, 1, 1, 1, 2, 2, 5, 5, 5, 9, 1, 1, 9, 5, 5]
+
 const astrings = ['b', 'b', 'a', 'b', 'z', 'a', 'a', 'd']
 
 const sstrings = ['a', 'a', 'a', 'b', 'b', 'b', 'd', 'z'] // astrings.sorted()
@@ -16,6 +18,7 @@ fn test_uniq() {
 	assert arrays.uniq(s) == [1, 2, 5, 9]
 	assert arrays.uniq(astrings) == ['b', 'a', 'b', 'z', 'a', 'd']
 	assert arrays.uniq(sstrings) == ['a', 'b', 'd', 'z']
+	assert arrays.uniq(many_repeats) == [1, 2, 5, 9, 1, 9, 5]
 }
 
 fn test_uniq_only() {
@@ -27,6 +30,7 @@ fn test_uniq_only() {
 	assert arrays.uniq_only(s) == [9]
 	assert arrays.uniq_only(astrings) == ['a', 'b', 'z', 'd']
 	assert arrays.uniq_only(sstrings) == ['d', 'z']
+	assert arrays.uniq_only(many_repeats) == [9, 9]
 }
 
 fn test_uniq_only_repeated() {
@@ -52,7 +56,8 @@ fn test_uniq_only_repeated() {
 	assert arrays.uniq_only_repeated([5, 5, 1, 5, 5, 2, 5, 5, 3, 5, 5]) == [5, 5, 5, 5]
 	assert arrays.uniq_only_repeated([5, 5, 5, 1, 5, 5, 2, 5, 5, 3, 5, 5]) == [5, 5, 5, 5]
 	assert arrays.uniq_only_repeated(a) == [5, 1]
-	assert arrays.uniq_only_repeated(s) == [1, 5]
+	assert arrays.uniq_only_repeated(s) == [1, 2, 5]
+	assert arrays.uniq_only_repeated(many_repeats) == [1, 2, 5, 1, 5]
 }
 
 fn test_uniq_all_repeated() {
@@ -80,10 +85,12 @@ fn test_uniq_all_repeated() {
 	assert arrays.uniq_all_repeated([5, 5, 5, 1, 5, 5, 2, 5, 5, 3, 5, 5]) == [5, 5, 5, 5, 5, 5,
 		5, 5, 5]
 	assert arrays.uniq_all_repeated(a) == [5, 5, 1, 1]
-	assert arrays.uniq_all_repeated(s) == [1, 1, 1, 1, 5, 5, 5]
+	assert arrays.uniq_all_repeated(s) == [1, 1, 1, 1, 2, 2, 5, 5, 5]
+	assert arrays.uniq_all_repeated(many_repeats) == [1, 1, 1, 1, 2, 2, 5, 5, 5, 1, 1, 5, 5]
 }
 
 fn test_distinct() {
 	assert arrays.distinct(a) == arrays.distinct(s)
 	assert arrays.distinct(a) == [1, 2, 5, 9]
+	assert arrays.distinct(many_repeats) == [1, 2, 5, 9]
 }