Fix #4093 - prevent redundant condition in presence of positive-int

Author: muglug

src/Psalm/Internal/Type/NegatedAssertionReconciler.php

@@ -315,8 +315,12 @@ private static function handleLiteralNegatedEquality(
 
         if ($scalar_type === 'int') {
             if ($existing_var_type->hasInt()) {
+                $scalar_value = substr($assertion, $bracket_pos + 1, -1);
+
                 if ($existing_int_types = $existing_var_type->getLiteralInts()) {
-                    $did_match_literal_type = true;
+                    if (!$existing_var_type->hasPositiveInt()) {
+                        $did_match_literal_type = true;
+                    }
 
                     if (isset($existing_int_types[$assertion])) {
                         $existing_var_type->removeType($assertion);

src/Psalm/Type/Union.php

@@ -857,6 +857,14 @@ public function hasInt()
         return isset($this->types['int']) || isset($this->types['array-key']) || $this->literal_int_types;
     }
 
+    /**
+     * @return bool
+     */
+    public function hasPositiveInt()
+    {
+        return isset($this->types['int']) && $this->types['int'] instanceof Type\Atomic\TPositiveInt;
+    }
+
     /**
      * @return bool
      */

tests/TypeReconciliation/ValueTest.php

@@ -756,6 +756,16 @@ public static function getValues() {
 
                     echo strlen($data);'
             ],
+            'negateValueInUnion' => [
+                '<?php
+                    function f(): int {
+                        $ret = 0;
+                        for ($i = 20; $i >= 0; $i--) {
+                            $ret = ($ret === 10) ? 1 : $ret + 1;
+                        }
+                        return $ret;
+                    }'
+            ],
         ];
     }