From 7cc0f65f114a170eb6c085695e7902654ff0b3b0 Mon Sep 17 00:00:00 2001
From: Matt Brown <github@muglug.com>
Date: Wed, 2 Dec 2020 01:47:49 -0500
Subject: [PATCH] =?UTF-8?q?Don=E2=80=99t=20do=20new=20isset=20conversion?=
 =?UTF-8?q?=20on=20try-set=20vars?=
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---
 .../Analyzer/Statements/Expression/AssertionFinder.php |  1 +
 tests/TryCatchTest.php                                 | 10 ++++++++++
 2 files changed, 11 insertions(+)

diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/AssertionFinder.php b/src/Psalm/Internal/Analyzer/Statements/Expression/AssertionFinder.php
index 8f7bb8dcc..d17d5c3dc 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/AssertionFinder.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/AssertionFinder.php
@@ -491,6 +491,7 @@ class AssertionFinder
                         && ($var_type = $source->node_data->getType($isset_var))
                         && !$var_type->isMixed()
                         && !$var_type->possibly_undefined
+                        && !$var_type->possibly_undefined_from_try
                         && $var_name !== '$_SESSION'
                     ) {
                         $if_types[$var_name] = [['!null']];
diff --git a/tests/TryCatchTest.php b/tests/TryCatchTest.php
index affa6e22e..8a154fd5a 100644
--- a/tests/TryCatchTest.php
+++ b/tests/TryCatchTest.php
@@ -465,6 +465,16 @@ class TryCatchTest extends TestCase
                 [],
                 '8.0'
             ],
+            'issetInCatch' => [
+                '<?php
+                    function foo() : void {
+                        try {
+                            $a = 0;
+                        } catch (Exception $e) {
+                            echo isset($a) ? $a : 1;
+                        }
+                    }'
+            ],
         ];
     }