Fix #371 - improve handling of do statements broken in loop refactor

src/Psalm/Checker/Statements/Block/LoopChecker.php

@@ -32,7 +32,8 @@ class LoopChecker
         array $stmts,
         array $pre_conditions,
         array $post_conditions,
-        LoopScope $loop_scope
+        LoopScope $loop_scope,
+        Context &$inner_context = null
     ) {
         $traverser = new PhpParser\NodeTraverser;
 

src/Psalm/Checker/StatementsChecker.php

@@ -677,7 +677,7 @@ class StatementsChecker extends SourceChecker implements StatementsSource
     {
         $do_context = clone $context;
 
-        LoopChecker::analyze($this, $stmt->stmts, [], [], new LoopScope($do_context, $context));
+        LoopChecker::analyze($this, $stmt->stmts, [], [], new LoopScope($do_context, $context), $inner_loop_context);
 
         foreach ($context->vars_in_scope as $var => $type) {
             if ($type->isMixed()) {
@@ -701,6 +701,15 @@ class StatementsChecker extends SourceChecker implements StatementsSource
             }
         }
 
+        // because it's a do {} while, inner loop vars belong to the main context
+        if ($inner_loop_context) {
+            foreach ($inner_loop_context->vars_in_scope as $var_id => $type) {
+                if (!isset($context->vars_in_scope[$var_id])) {
+                    $context->vars_in_scope[$var_id] = $type;
+                }
+            }
+        }
+
         $context->vars_possibly_in_scope = array_merge(
             $context->vars_possibly_in_scope,
             $do_context->vars_possibly_in_scope

tests/LoopScopeTest.php

@@ -111,6 +111,12 @@ class LoopScopeTest extends TestCase
                     '$worked' => 'bool',
                 ],
             ],
+            'doWhileUndefinedVar' => [
+                '<?php
+                    do {
+                        $result = rand(0,1);
+                    } while (!$result);',
+            ],
             'doWhileVarAndBreak' => [
                 '<?php
                     /** @return void */