From c5ee1fec37a655859b3fcdc42a1ef0011a3cc40a Mon Sep 17 00:00:00 2001
From: Abdul Malik Ikhsan <samsonasik@gmail.com>
Date: Tue, 28 Jul 2026 16:12:57 +0700
Subject: [PATCH 1/2] [DeadCode] Skip negative zero on
 RemoveDeadZeroAndOneOperationRector

---
 .../Fixture/skip_negative_zero.php.inc        | 15 +++++++++++
 .../RemoveDeadZeroAndOneOperationRector.php   | 25 ++++++++++++++++++-
 2 files changed, 39 insertions(+), 1 deletion(-)
 create mode 100644 rules-tests/DeadCode/Rector/Plus/RemoveDeadZeroAndOneOperationRector/Fixture/skip_negative_zero.php.inc

diff --git a/rules-tests/DeadCode/Rector/Plus/RemoveDeadZeroAndOneOperationRector/Fixture/skip_negative_zero.php.inc b/rules-tests/DeadCode/Rector/Plus/RemoveDeadZeroAndOneOperationRector/Fixture/skip_negative_zero.php.inc
new file mode 100644
index 00000000000..9f7af43a966
--- /dev/null
+++ b/rules-tests/DeadCode/Rector/Plus/RemoveDeadZeroAndOneOperationRector/Fixture/skip_negative_zero.php.inc
@@ -0,0 +1,15 @@
+<?php
+
+namespace Rector\Tests\DeadCode\Rector\Plus\RemoveDeadZeroAndOneOperationRector\Fixture;
+
+final class SkipNegativeZero
+{
+    protected function run()
+    {
+        $value = round(-0.001, 2);
+        var_dump((string) $value);
+
+        $value = $value + 0;
+        var_dump((string) $value);
+    }
+}
diff --git a/rules/DeadCode/Rector/Plus/RemoveDeadZeroAndOneOperationRector.php b/rules/DeadCode/Rector/Plus/RemoveDeadZeroAndOneOperationRector.php
index d48918c6b11..10d56a30ce1 100644
--- a/rules/DeadCode/Rector/Plus/RemoveDeadZeroAndOneOperationRector.php
+++ b/rules/DeadCode/Rector/Plus/RemoveDeadZeroAndOneOperationRector.php
@@ -100,6 +100,11 @@ private function processAssignOp(AssignOp $assignOp): ?Expr
                 return null;
             }
 
+            // on float, += 0 normalizes negative zero (-0.0) to 0.0, so it is not dead
+            if ($assignOp instanceof AssignPlus && ! $this->isIntegerType($assignOp->var)) {
+                return null;
+            }
+
             if ($this->nodeTypeResolver->isNumberType($assignOp->var)) {
                 return $assignOp->var;
             }
@@ -152,7 +157,13 @@ private function processBinaryPlusAndMinus(Plus|Minus $binaryOp): ?Expr
             return null;
         }
 
-        if ($this->isLiteralZero($binaryOp->left) && $this->nodeTypeResolver->isNumberType($binaryOp->right)) {
+        if ($this->isLiteralZero($binaryOp->left)) {
+            // on float, 0 + $x normalizes negative zero (-0.0) to 0.0 and 0 - $x flips its sign,
+            // so the operation is not dead
+            if (! $this->isIntegerType($binaryOp->right)) {
+                return null;
+            }
+
             if ($binaryOp instanceof Minus) {
                 return new UnaryMinus($binaryOp->right);
             }
@@ -164,6 +175,11 @@ private function processBinaryPlusAndMinus(Plus|Minus $binaryOp): ?Expr
             return null;
         }
 
+        // on float, $x + 0 normalizes negative zero (-0.0) to 0.0, so it is not dead
+        if ($binaryOp instanceof Plus && ! $this->isIntegerType($binaryOp->left)) {
+            return null;
+        }
+
         return $binaryOp->left;
     }
 
@@ -237,4 +253,11 @@ private function isLiteralZero(Expr $expr): bool
     {
         return $expr instanceof Int_ && $expr->value === 0;
     }
+
+    private function isIntegerType(Expr $expr): bool
+    {
+        return $this->nodeTypeResolver->getNativeType($expr)
+            ->isInteger()
+            ->yes();
+    }
 }

From cbeb7c162f0c49f99bb35ddd364796e546483d85 Mon Sep 17 00:00:00 2001
From: Abdul Malik Ikhsan <samsonasik@gmail.com>
Date: Tue, 28 Jul 2026 16:16:20 +0700
Subject: [PATCH 2/2] assignplus

---
 .../skip_assign_plus_negative_zero.php.inc    | 15 +++++++++++++++
 .../skip_zero_minus_positive_zero.php.inc     | 15 +++++++++++++++
 .../skip_zero_plus_negative_zero.php.inc      | 15 +++++++++++++++
 .../RemoveDeadZeroAndOneOperationRector.php   | 19 +++++++++----------
 4 files changed, 54 insertions(+), 10 deletions(-)
 create mode 100644 rules-tests/DeadCode/Rector/Plus/RemoveDeadZeroAndOneOperationRector/Fixture/skip_assign_plus_negative_zero.php.inc
 create mode 100644 rules-tests/DeadCode/Rector/Plus/RemoveDeadZeroAndOneOperationRector/Fixture/skip_zero_minus_positive_zero.php.inc
 create mode 100644 rules-tests/DeadCode/Rector/Plus/RemoveDeadZeroAndOneOperationRector/Fixture/skip_zero_plus_negative_zero.php.inc

diff --git a/rules-tests/DeadCode/Rector/Plus/RemoveDeadZeroAndOneOperationRector/Fixture/skip_assign_plus_negative_zero.php.inc b/rules-tests/DeadCode/Rector/Plus/RemoveDeadZeroAndOneOperationRector/Fixture/skip_assign_plus_negative_zero.php.inc
new file mode 100644
index 00000000000..8a34b5029ab
--- /dev/null
+++ b/rules-tests/DeadCode/Rector/Plus/RemoveDeadZeroAndOneOperationRector/Fixture/skip_assign_plus_negative_zero.php.inc
@@ -0,0 +1,15 @@
+<?php
+
+namespace Rector\Tests\DeadCode\Rector\Plus\RemoveDeadZeroAndOneOperationRector\Fixture;
+
+final class SkipAssignPlusNegativeZero
+{
+    protected function run()
+    {
+        $value = round(-0.001, 2);
+        var_dump((string) $value);
+
+        $value += 0;
+        var_dump((string) $value);
+    }
+}
diff --git a/rules-tests/DeadCode/Rector/Plus/RemoveDeadZeroAndOneOperationRector/Fixture/skip_zero_minus_positive_zero.php.inc b/rules-tests/DeadCode/Rector/Plus/RemoveDeadZeroAndOneOperationRector/Fixture/skip_zero_minus_positive_zero.php.inc
new file mode 100644
index 00000000000..8b8e19512f1
--- /dev/null
+++ b/rules-tests/DeadCode/Rector/Plus/RemoveDeadZeroAndOneOperationRector/Fixture/skip_zero_minus_positive_zero.php.inc
@@ -0,0 +1,15 @@
+<?php
+
+namespace Rector\Tests\DeadCode\Rector\Plus\RemoveDeadZeroAndOneOperationRector\Fixture;
+
+final class SkipZeroMinusPositiveZero
+{
+    protected function run()
+    {
+        $value = 0.0;
+        var_dump((string) $value);
+
+        $value = 0 - $value;
+        var_dump((string) $value);
+    }
+}
diff --git a/rules-tests/DeadCode/Rector/Plus/RemoveDeadZeroAndOneOperationRector/Fixture/skip_zero_plus_negative_zero.php.inc b/rules-tests/DeadCode/Rector/Plus/RemoveDeadZeroAndOneOperationRector/Fixture/skip_zero_plus_negative_zero.php.inc
new file mode 100644
index 00000000000..0b870bb46ad
--- /dev/null
+++ b/rules-tests/DeadCode/Rector/Plus/RemoveDeadZeroAndOneOperationRector/Fixture/skip_zero_plus_negative_zero.php.inc
@@ -0,0 +1,15 @@
+<?php
+
+namespace Rector\Tests\DeadCode\Rector\Plus\RemoveDeadZeroAndOneOperationRector\Fixture;
+
+final class SkipZeroPlusNegativeZero
+{
+    protected function run()
+    {
+        $value = round(-0.001, 2);
+        var_dump((string) $value);
+
+        $value = 0 + $value;
+        var_dump((string) $value);
+    }
+}
diff --git a/rules/DeadCode/Rector/Plus/RemoveDeadZeroAndOneOperationRector.php b/rules/DeadCode/Rector/Plus/RemoveDeadZeroAndOneOperationRector.php
index 10d56a30ce1..d27f08f35d6 100644
--- a/rules/DeadCode/Rector/Plus/RemoveDeadZeroAndOneOperationRector.php
+++ b/rules/DeadCode/Rector/Plus/RemoveDeadZeroAndOneOperationRector.php
@@ -101,7 +101,9 @@ private function processAssignOp(AssignOp $assignOp): ?Expr
             }
 
             // on float, += 0 normalizes negative zero (-0.0) to 0.0, so it is not dead
-            if ($assignOp instanceof AssignPlus && ! $this->isIntegerType($assignOp->var)) {
+            if ($assignOp instanceof AssignPlus && ! $this->nodeTypeResolver->getNativeType($assignOp->var)
+                ->isInteger()
+                ->yes()) {
                 return null;
             }
 
@@ -160,7 +162,9 @@ private function processBinaryPlusAndMinus(Plus|Minus $binaryOp): ?Expr
         if ($this->isLiteralZero($binaryOp->left)) {
             // on float, 0 + $x normalizes negative zero (-0.0) to 0.0 and 0 - $x flips its sign,
             // so the operation is not dead
-            if (! $this->isIntegerType($binaryOp->right)) {
+            if (! $this->nodeTypeResolver->getNativeType($binaryOp->right)
+                ->isInteger()
+                ->yes()) {
                 return null;
             }
 
@@ -176,7 +180,9 @@ private function processBinaryPlusAndMinus(Plus|Minus $binaryOp): ?Expr
         }
 
         // on float, $x + 0 normalizes negative zero (-0.0) to 0.0, so it is not dead
-        if ($binaryOp instanceof Plus && ! $this->isIntegerType($binaryOp->left)) {
+        if ($binaryOp instanceof Plus && ! $this->nodeTypeResolver->getNativeType($binaryOp->left)
+            ->isInteger()
+            ->yes()) {
             return null;
         }
 
@@ -253,11 +259,4 @@ private function isLiteralZero(Expr $expr): bool
     {
         return $expr instanceof Int_ && $expr->value === 0;
     }
-
-    private function isIntegerType(Expr $expr): bool
-    {
-        return $this->nodeTypeResolver->getNativeType($expr)
-            ->isInteger()
-            ->yes();
-    }
 }