Fix #2197 - prevent false positive from try in while

src/Psalm/Internal/Analyzer/Statements/Block/TryAnalyzer.php

@@ -414,6 +414,20 @@ function ($fq_catch_class) use ($codebase) {
                     $statements_analyzer->registerVariableUses($locations);
                 }
             }
+
+            $newly_unreferenced_vars = array_merge(
+                $newly_unreferenced_vars,
+                array_diff_key(
+                    $try_context->unreferenced_vars,
+                    $old_unreferenced_vars
+                )
+            );
+
+            foreach ($newly_unreferenced_vars as $var_id => $locations) {
+                if (!isset($context->unreferenced_vars[$var_id])) {
+                    $context->unreferenced_vars[$var_id] = $locations;
+                }
+            }
         }
 
         if ($stmt->finally) {

tests/UnusedVariableTest.php

@@ -1171,6 +1171,29 @@ function b(): void {
                         echo $b;
                     }'
             ],
+            'tryWithWhile' => [
+                '<?php
+                    function foo(): void {
+                        $done = false;
+
+                        while (!$done) {
+                            try {
+                                $done = true;
+                            } catch (\Exception $e) {
+                            }
+                        }
+                    }',
+            ],
+            'tryWithWhileWithoutTry' => [
+                '<?php
+                    function foo(): void {
+                        $done = false;
+
+                        while (!$done) {
+                            $done = true;
+                        }
+                    }',
+            ],
         ];
     }