Fix div by zero errors

Author: ondrejmirtes

src/Analyser/MutatingScope.php

@@ -1335,8 +1335,8 @@ private function resolveType(Expr $node): Type
 					$min = $leftMin !== null && $rightMin !== null ? $leftMin * $rightMin : null;
 					$max = $leftMax !== null && $rightMax !== null ? $leftMax * $rightMax : null;
 				} else {
-					$min = $leftMin !== null && $rightMin !== null ? (int) ($leftMin / $rightMin) : null;
-					$max = $leftMax !== null && $rightMax !== null ? (int) ($leftMax / $rightMax) : null;
+					$min = $leftMin !== null && $rightMin !== null && $rightMin !== 0 ? (int) ($leftMin / $rightMin) : null;
+					$max = $leftMax !== null && $rightMax !== null && $rightMax !== 0 ? (int) ($leftMax / $rightMax) : null;
 
 					if ($min !== null && $max !== null && $min > $max) {
 						[$min, $max] = [$max, $min];

tests/PHPStan/Analyser/NodeScopeResolverTest.php

@@ -485,6 +485,8 @@ public function dataFileAsserts(): iterable
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-5529.php');
 
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/sizeof.php');
+
+		yield from $this->gatherAssertTypes(__DIR__ . '/data/div-by-zero.php');
 	}
 
 	/**

tests/PHPStan/Analyser/data/div-by-zero.php

@@ -0,0 +1,21 @@
+<?php
+
+namespace DivByZero;
+
+use function PHPStan\Testing\assertType;
+
+class Foo
+{
+
+	/**
+	 * @param int<0, max> $range1
+	 * @param int<min, 0> $range2
+	 */
+	public function doFoo(int $range1, int $range2): void
+	{
+		assertType('(float|int)', 5 / $range1);
+		assertType('(float|int)', 5 / $range2);
+		assertType('*ERROR*', 5 / 0);
+	}
+
+}