From 33f003f427cbbe064e20c84233fea6a39374ef97 Mon Sep 17 00:00:00 2001
From: Matt Brown <github@muglug.com>
Date: Tue, 28 Nov 2017 16:52:52 -0500
Subject: [PATCH] =?UTF-8?q?Don=E2=80=99t=20complain=20about=20repeat=20iss?=
 =?UTF-8?q?et=20calls=20on=20array=20keys?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Fixes #347
---
 src/Psalm/Checker/AlgebraChecker.php             |  8 +++++---
 src/Psalm/Checker/Statements/Block/IfChecker.php |  4 +++-
 src/Psalm/Checker/TypeChecker.php                |  6 +++---
 tests/IssetTest.php                              | 12 ++++++++++++
 4 files changed, 23 insertions(+), 7 deletions(-)

diff --git a/src/Psalm/Checker/AlgebraChecker.php b/src/Psalm/Checker/AlgebraChecker.php
index 16ec90af9..72474a875 100644
--- a/src/Psalm/Checker/AlgebraChecker.php
+++ b/src/Psalm/Checker/AlgebraChecker.php
@@ -97,7 +97,7 @@ class AlgebraChecker
 
                     $base = array_shift($key_parts);
 
-                    $clauses[] = new Clause([$base => ['isset']]);
+                    $clauses[] = new Clause([$base => ['^isset']]);
 
                     if (count($key_parts)) {
                         $clauses[] = new Clause([$base => ['!false']]);
@@ -106,7 +106,7 @@ class AlgebraChecker
 
                     foreach ($key_parts as $i => $key_part_dim) {
                         $base .= '[' . $key_part_dim . ']';
-                        $clauses[] = new Clause([$base => ['isset']]);
+                        $clauses[] = new Clause([$base => ['^isset']]);
 
                         if ($i < count($key_parts) - 1) {
                             $clauses[] = new Clause([$base => ['!false']]);
@@ -208,7 +208,9 @@ class AlgebraChecker
         // remove impossible types
         foreach ($negated_formula2 as $clause_a) {
             foreach ($clause_a->possibilities as $key => $values) {
-                if (count($values) > 1 && count(array_unique($values)) < count($values)) {
+                if (count($values) > 1
+                    && count(array_unique($values)) < count($values)
+                ) {
                     if (IssueBuffer::accepts(
                         new RedundantCondition(
                             'Found a redundant condition when evaluating ' . $key,
diff --git a/src/Psalm/Checker/Statements/Block/IfChecker.php b/src/Psalm/Checker/Statements/Block/IfChecker.php
index 21c935582..f4f331c10 100644
--- a/src/Psalm/Checker/Statements/Block/IfChecker.php
+++ b/src/Psalm/Checker/Statements/Block/IfChecker.php
@@ -404,7 +404,9 @@ class IfChecker
 
             // if we have a check like if (!isset($a)) { $a = true; } we want to make sure $a is always set
             foreach ($if_scope->new_vars as $var_id => $_) {
-                if (isset($if_scope->negated_types[$var_id]) && $if_scope->negated_types[$var_id] === 'isset') {
+                if (isset($if_scope->negated_types[$var_id])
+                    && ($if_scope->negated_types[$var_id] === 'isset' || $if_scope->negated_types[$var_id] === '^isset')
+                ) {
                     $if_scope->forced_new_vars[$var_id] = Type::getMixed();
                 }
             }
diff --git a/src/Psalm/Checker/TypeChecker.php b/src/Psalm/Checker/TypeChecker.php
index 9541d8db6..0c2909213 100644
--- a/src/Psalm/Checker/TypeChecker.php
+++ b/src/Psalm/Checker/TypeChecker.php
@@ -113,7 +113,7 @@ class TypeChecker
                         return false;
                     }
 
-                    $orred_type = $orred_type && $result_type_candidate
+                    $orred_type = $orred_type
                         ? Type::combineUnionTypes($result_type_candidate, $orred_type)
                         : $result_type_candidate;
                 }
@@ -156,7 +156,7 @@ class TypeChecker
      * @param   array               $suppressed_issues
      * @param   bool                $failed_reconciliation if the types cannot be reconciled, we need to know
      *
-     * @return  Type\Union|null|false
+     * @return  Type\Union|false
      */
     public static function reconcileTypes(
         $new_var_type,
@@ -171,7 +171,7 @@ class TypeChecker
 
         if ($existing_var_type === null) {
             if ($new_var_type === '^isset') {
-                return null;
+                return Type::getMixed();
             }
 
             if ($new_var_type === 'isset') {
diff --git a/tests/IssetTest.php b/tests/IssetTest.php
index 8507ef7ae..ea06d2529 100644
--- a/tests/IssetTest.php
+++ b/tests/IssetTest.php
@@ -75,6 +75,18 @@ class IssetTest extends TestCase
                     '$foo' => \Psalm\Type::getArray(),
                 ],
             ],
+            'noRedundantConditionOnMixed' => [
+                '<?php
+                    function testarray(array $data) : void {
+                        foreach ($data as $item) {
+                            if (isset($item["a"]) && isset($item["b"]) && isset($item["b"]["c"])) {
+                                echo "Found\n";
+                            }
+                        }
+                    }',
+                'assertions' => [],
+                'error_levels' => ['MixedAssignment'],
+            ],
         ];
     }
 }