Fix spurious error nullCoalesce.offset

Author: staabm

src/Analyser/ExprHandler/Helper/NonNullabilityHelper.php

@@ -30,12 +30,7 @@ public function ensureShallowNonNullability(MutatingScope $scope, Scope $origina
 		}
 
 		// keep certainty
-		$certainty = TrinaryLogic::createYes();
-		$hasExpressionType = $originalScope->hasExpressionType($exprToSpecify);
-		if (!$hasExpressionType->no()) {
-			$certainty = $hasExpressionType;
-		}
-
+		$certainty = $originalScope->hasExpressionType($exprToSpecify);
 		$exprTypeWithoutNull = TypeCombinator::removeNull($exprType);
 		if ($exprType->equals($exprTypeWithoutNull)) {
 			$originalExprType = $originalScope->getType($exprToSpecify);
@@ -107,6 +102,10 @@ public function ensureNonNullability(MutatingScope $scope, Expr $expr): EnsuredN
 	public function revertNonNullability(MutatingScope $scope, array $specifiedExpressions): MutatingScope
 	{
 		foreach ($specifiedExpressions as $specifiedExpressionResult) {
+			if ($specifiedExpressionResult->getCertainty()->no()) {
+				$scope = $scope->invalidateExpression($specifiedExpressionResult->getExpression());
+				continue;
+			}
 			$scope = $scope->specifyExpressionType(
 				$specifiedExpressionResult->getExpression(),
 				$specifiedExpressionResult->getOriginalType(),

tests/PHPStan/Analyser/nsrt/has-offset-type-bug.php

@@ -105,7 +105,7 @@ public function doFoo2($mixed)
 	public function doBar(\SimpleXMLElement $xml)
 	{
 		if (isset($xml['foo'])) {
-			assertType('SimpleXMLElement', $xml['foo']);
+			assertType("SimpleXMLElement&hasOffset('foo')", $xml['foo']);
 			assertType("SimpleXMLElement&hasOffset('foo')", $xml);
 		}
 	}