Use SORT_STRING for canonicalized query generation, add test new behavior

Author: simonkey

src/Signature/SignatureV4.php

@@ -356,7 +356,7 @@ private function getCanonicalizedQuery(array $query)
             if (!is_array($v)) {
                 $qs .= rawurlencode($k) . '=' . rawurlencode($v !== null ? $v : '') . '&';
             } else {
-                sort($v);
+                sort($v, SORT_STRING);
                 foreach ($v as $value) {
                     $qs .= rawurlencode($k) . '=' . rawurlencode($value !== null ? $value : '') . '&';
                 }

tests/Signature/SignatureV4Test.php

@@ -367,6 +367,20 @@ public function testCanonicalQuerySortingOccursAfterEncoding()
         $this->assertSame($expectedSigned, Psr7\Message::toString($signed));
     }
 
+    public function testCanonicalizedQuerySortingParameterMultiOccurrenceNumericValues(): void
+    {
+        $signature = new SignatureV4('service', 'region');
+
+        $canonicalizedQuery = new \ReflectionMethod($signature, 'getCanonicalizedQuery');
+        $parameters = [
+            'parameter1' => ['100', '50'],
+            'parameter2' => 'value',
+        ];
+
+        $query = $canonicalizedQuery->invoke($signature, $parameters);
+        $this->assertSame('parameter1=100&parameter1=50&parameter2=value', $query);
+    }
+
     public function testEnsuresContentSha256CanBeCalculated()
     {
         $this->expectException(\Aws\Exception\CouldNotCreateChecksumException::class);