Improve accuracy of array nesting checks

src/Psalm/Internal/Codebase/Taint.php

@@ -232,11 +232,21 @@ class Taint
             }
 
             if (strpos($path_type, 'array-fetch-') === 0) {
+                $fetch_nesting = 0;
+
                 $previous_path_types = array_reverse($generated_source->path_types);
 
                 foreach ($previous_path_types as $previous_path_type) {
                     if ($previous_path_type === 'array-assignment') {
-                        break;
+                        if ($fetch_nesting === 0) {
+                            break;
+                        }
+
+                        $fetch_nesting--;
+                    }
+
+                    if ($previous_path_type === 'array-fetch') {
+                        $fetch_nesting++;
                     }
 
                     if (strpos($previous_path_type, 'array-assignment-') === 0) {

tests/TaintTest.php

@@ -418,6 +418,15 @@ class TaintTest extends TestCase
 
                     echo StringUtility::slugify("hello");'
             ],
+            'taintFreeNestedArray' => [
+                '<?php
+                    $a = [];
+                    $a[] = ["a" => $_GET["name"], "b" => "foo"];
+
+                    foreach ($a as $m) {
+                        echo $m["b"];
+                    }'
+            ],
         ];
     }