IntegerRangeMath: cover more maxima cases

Author: staabm

src/Analyser/MutatingScope.php

@@ -5300,6 +5300,15 @@ private function integerRangeMath(Type $range, Expr $node, Type $operand): Type
 				$max = $rangeMax !== null && $operand->getMax() !== null && $operand->getMax() !== 0 ? $rangeMax / $operand->getMax() : null;
 			}
 
+			if ($range instanceof IntegerRangeType && $operand instanceof IntegerRangeType) {
+				if ($rangeMax === null && $operand->getMax() === null) {
+					$min = 0;
+				} elseif ($rangeMin === null && $operand->getMin() === null) {
+					$min = null;
+					$max = null;
+				}
+			}
+
 			if ($operand instanceof IntegerRangeType
 				&& ($operand->getMin() === null || $operand->getMax() === null)
 				|| ($rangeMin === null || $rangeMax === null)

tests/PHPStan/Analyser/data/integer-range-types.php

@@ -281,6 +281,16 @@ public function math($i, $j, $z, $pi, $r1, $r2, $r3, $rMin, $rMax, $x, $y) {
 
 		assertType('5|10|15|20|30', $x / $y);
 
+		assertType('float|int<0, max>', $rMax / $rMax);
+		assertType('(float|int)', $rMin / $rMin);
+	}
+
+	/**
+	 * @param int<0, max> $a
+	 * @param int<0, max> $b
+	 */
+	function divisionLoosesInformation(int $a, int $b): void {
+		assertType('float|int<0, max>',$a/$b);
 	}
 
 	/**