urllib: fixed regression in the set function (#13455)

vlib/net/urllib/values.v

@@ -57,13 +57,21 @@ pub fn (v &Values) get_all(key string) []string {
 }
 
 // set sets the key to value. It replaces any existing
-// values.
+// values, or create a new bucket with the new key if it is missed.
 pub fn (mut v Values) set(key string, value string) {
 	// A query string can contains several
 	// duplicate, so we need to make sure that we
 	// cover all the edge case.
+	mut found := false
 	for mut qvalue in v.data {
-		qvalue.value = value
+		if qvalue.key == key {
+			found = true
+			qvalue.value = value
+		}
+	}
+
+	if !found {
+		v.add(key, value)
 	}
 }
 

vlib/net/urllib/values_test.v

@@ -0,0 +1,38 @@
+// Copyright (c) 2019-2022 Alexander Medvednikov. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+module urllib
+
+fn test_add_key_val() {
+	mut values := Values{}
+	values.add('key', 'value')
+	val := values.get('key')
+	assert val == 'value'
+}
+
+fn test_get_all_with_key() {
+	mut values := Values{}
+	values.add('key', 'value1')
+	values.add('key', 'value2')
+	key_values := values.get_all('key')
+	assert key_values == ['value1', 'value2']
+}
+
+fn test_set_with_key() {
+	mut values := Values{}
+	values.add('key', 'value1')
+	values.add('key', 'value2')
+	values.add('key1', 'value2')
+	values.set('key1', 'vlang')
+	key_values := values.get_all('key')
+	key2_values := values.get_all('key1')
+	assert key_values == ['value1', 'value2']
+	assert key2_values == ['vlang']
+}
+
+fn test_set_missing_key() {
+	mut values := Values{}
+	values.set('err', 'err1')
+	vals := values.get_all('err')
+	assert vals == ['err1']
+}