Squiz/DisallowMultipleAssignments: fix false positive when handling parameter default values

src/Standards/Squiz/Sniffs/PHP/DisallowMultipleAssignmentsSniff.php

@@ -45,6 +45,11 @@ public function process(File $phpcsFile, $stackPtr)
         // Ignore default value assignments in function definitions.
         $function = $phpcsFile->findPrevious([T_FUNCTION, T_CLOSURE, T_FN], ($stackPtr - 1), null, false, null, true);
         if ($function !== false) {
+            if (isset($tokens[$function]['parenthesis_closer']) === false) {
+                // Live coding/parse error. Bow out.
+                return;
+            }
+
             $opener = $tokens[$function]['parenthesis_opener'];
             $closer = $tokens[$function]['parenthesis_closer'];
             if ($opener < $stackPtr && $closer > $stackPtr) {

src/Standards/Squiz/Tests/PHP/DisallowMultipleAssignmentsUnitTest.2.inc

@@ -0,0 +1,7 @@
+<?php
+
+// Intentional parse error (missing closing parenthesis).
+// This should be the only test in this file.
+// Testing that the sniff is *not* triggered.
+
+function missingClosingParenthesis($a =

src/Standards/Squiz/Tests/PHP/DisallowMultipleAssignmentsUnitTest.php

@@ -26,21 +26,29 @@ final class DisallowMultipleAssignmentsUnitTest extends AbstractSniffUnitTest
      * The key of the array should represent the line number and the value
      * should represent the number of errors that should occur on that line.
      *
+     * @param string $testFile The name of the test file to process.
+     *
      * @return array<int, int>
      */
-    public function getErrorList()
+    public function getErrorList($testFile='')
     {
-        return [
-            4  => 1,
-            5  => 2,
-            7  => 1,
-            9  => 1,
-            12 => 1,
-            14 => 1,
-            15 => 1,
-            79 => 1,
-            85 => 1,
-        ];
+        switch ($testFile) {
+        case 'DisallowMultipleAssignmentsUnitTest.1.inc':
+            return [
+                4  => 1,
+                5  => 2,
+                7  => 1,
+                9  => 1,
+                12 => 1,
+                14 => 1,
+                15 => 1,
+                79 => 1,
+                85 => 1,
+            ];
+
+        default:
+            return [];
+        }
 
     }//end getErrorList()