Avoid issue with multiplication by 0

phpstan · Nov 4, 2022 · 968b0ab · 968b0ab
1 parent 44da600
commit 968b0ab
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Showing 2 changed files with 16 additions and 4 deletions.
diff --git a/src/Reflection/InitializerExprTypeResolver.php b/src/Reflection/InitializerExprTypeResolver.php
@@ -1627,10 +1627,10 @@ private function integerRangeMath(Type $range, BinaryOp $node, Type $operand): T
 				}
 			}
 		} elseif ($node instanceof Expr\BinaryOp\Mul) {
-			$min1 = ($rangeMin ?? -INF) * ($operandMin ?? -INF);
-			$min2 = ($rangeMin ?? -INF) * ($operandMax ?? INF);
-			$max1 = ($rangeMax ?? INF) * ($operandMin ?? -INF);
-			$max2 = ($rangeMax ?? INF) * ($operandMax ?? INF);
+			$min1 = $rangeMin === 0 || $operandMin === 0 ? 0 : ($rangeMin ?? -INF) * ($operandMin ?? -INF);
+			$min2 = $rangeMin === 0 || $operandMax === 0 ? 0 : ($rangeMin ?? -INF) * ($operandMax ?? INF);
+			$max1 = $rangeMax === 0 || $operandMin === 0 ? 0 : ($rangeMax ?? INF) * ($operandMin ?? -INF);
+			$max2 = $rangeMax === 0 || $operandMax === 0 ? 0 : ($rangeMax ?? INF) * ($operandMax ?? INF);
 
 			$min = min($min1, $min2, $max1, $max2);
 			$max = max($min1, $min2, $max1, $max2);

diff --git a/tests/PHPStan/Analyser/data/integer-range-types.php b/tests/PHPStan/Analyser/data/integer-range-types.php
@@ -342,4 +342,16 @@ public function sayHello($p, $u): void
 		assertType('float|int<-2, 2>', $p / $u);
 	}
 
+	/**
+	 * @param int<0, max> $positive
+	 * @param int<min, 0> $negative
+	 */
+	public function zeroIssues($positive, $negative)
+	{
+		assertType('0', 0 * $positive);
+		assertType('int<0, max>', $positive * $positive);
+		assertType('0', 0 * $negative);
+		assertType('int<0, max>', $negative * $negative);
+	}
+
 }