From 8266b305ace6ba225d56c79fea27b87a6264171a Mon Sep 17 00:00:00 2001
From: Kevin van Sonsbeek <kevin_787@msn.com>
Date: Fri, 7 Feb 2025 19:33:41 +0100
Subject: [PATCH 1/4] bugfix(#11241): Add test cases for addition and
 subtraction

---
 tests/BinaryOperationTest.php | 38 +++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)

diff --git a/tests/BinaryOperationTest.php b/tests/BinaryOperationTest.php
index 5ecc5533326..13a995e4f8e 100644
--- a/tests/BinaryOperationTest.php
+++ b/tests/BinaryOperationTest.php
@@ -592,6 +592,44 @@ function scope(){
                     '$b' => 'float',
                 ],
             ],
+            'intArithmeticAssignmentAdditionFromFunction' => [
+                'code' => '<?php
+                    function intFunc(): int {
+                        return 5;
+                    }
+                    $a = 1;
+                    $a += intFunc();',
+                'assertions' => [
+                    '$a===' => 'int',
+                ],
+            ],
+            'intArithmeticAssignmentAddition' => [
+                'code' => '<?php
+                    $a = 1;
+                    $a += 5;',
+                'assertions' => [
+                    '$a===' => '6',
+                ],
+            ],
+            'intArithmeticAssignmentSubtractionFromFunction' => [
+                'code' => '<?php
+                    function intFunc(): int {
+                        return 5;
+                    }
+                    $a = 8;
+                    $a -= intFunc();',
+                'assertions' => [
+                    '$a===' => 'int',
+                ],
+            ],
+            'intArithmeticAssignmentSubtraction' => [
+                'code' => '<?php
+                    $a = 8;
+                    $a -= 5;',
+                'assertions' => [
+                    '$a===' => '3',
+                ],
+            ],
             'exponent' => [
                 'code' => '<?php
                     $b = 4 ** 5;',

From 886a9e6fa71837a2126ecb36692df7bc54c26417 Mon Sep 17 00:00:00 2001
From: Kevin van Sonsbeek <kevin_787@msn.com>
Date: Fri, 7 Feb 2025 20:42:18 +0100
Subject: [PATCH 2/4] bugfix(#11241): Set type to TInt if the VirtualPlus or
 VirtualMinus is performed in the context of an assignment

---
 .../Statements/Expression/BinaryOp/ArithmeticOpAnalyzer.php | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/BinaryOp/ArithmeticOpAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/Expression/BinaryOp/ArithmeticOpAnalyzer.php
index 10d14b45f18..387cf93ba41 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/BinaryOp/ArithmeticOpAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/BinaryOp/ArithmeticOpAnalyzer.php
@@ -831,7 +831,11 @@ private static function analyzeOperands(
                                 $new_type = new TIntRange(null, $left_type_part->value + $sum);
                             }
                         } elseif ($left_type_part instanceof TLiteralInt) {
-                            $new_type = new TLiteralInt($left_type_part->value + $sum);
+                            if ($context->inside_assignment) {
+                                $new_type = new TInt();
+                            } else {
+                                $new_type = new TLiteralInt($left_type_part->value + $sum);
+                            }
                         } elseif ($left_type_part instanceof TIntRange) {
                             $start = $left_type_part->min_bound === null ? null : $left_type_part->min_bound + $sum;
                             $end = $left_type_part->max_bound === null ? null : $left_type_part->max_bound + $sum;

From e7b79b56e918242ac99689e3ed678414ea53aacf Mon Sep 17 00:00:00 2001
From: Kevin van Sonsbeek <kevin_787@msn.com>
Date: Fri, 7 Feb 2025 21:04:24 +0100
Subject: [PATCH 3/4] bugfix(#11241): Add missing check to see if context is
 set

---
 .../Statements/Expression/BinaryOp/ArithmeticOpAnalyzer.php     | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/BinaryOp/ArithmeticOpAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/Expression/BinaryOp/ArithmeticOpAnalyzer.php
index 387cf93ba41..264fb7c9003 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/BinaryOp/ArithmeticOpAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/BinaryOp/ArithmeticOpAnalyzer.php
@@ -831,7 +831,7 @@ private static function analyzeOperands(
                                 $new_type = new TIntRange(null, $left_type_part->value + $sum);
                             }
                         } elseif ($left_type_part instanceof TLiteralInt) {
-                            if ($context->inside_assignment) {
+                            if ($context && $context->inside_assignment) {
                                 $new_type = new TInt();
                             } else {
                                 $new_type = new TLiteralInt($left_type_part->value + $sum);

From 9b6734d0729b0216491d54c4fb914e319fc5cfd9 Mon Sep 17 00:00:00 2001
From: Kevin van Sonsbeek <kevin_787@msn.com>
Date: Mon, 10 Feb 2025 17:42:54 +0100
Subject: [PATCH 4/4] bugfix(#11241): Add comment

---
 .../Statements/Expression/BinaryOp/ArithmeticOpAnalyzer.php     | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/BinaryOp/ArithmeticOpAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/Expression/BinaryOp/ArithmeticOpAnalyzer.php
index 264fb7c9003..4d87d3749d3 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/BinaryOp/ArithmeticOpAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/BinaryOp/ArithmeticOpAnalyzer.php
@@ -823,6 +823,8 @@ private static function analyzeOperands(
                             }
                         }
                     } elseif ($parent instanceof VirtualPlus || $parent instanceof VirtualMinus) {
+                        // This seems arbitrary defined as 1/-1, to facilitate loops
+                        // and may need a better handling if there's issues
                         $sum = $parent instanceof VirtualPlus ? 1 : -1;
                         if ($context && $context->inside_loop && $left_type_part instanceof TLiteralInt) {
                             if ($parent instanceof VirtualPlus) {