array_key_exist inference is lost when adding a false condition

src/Analyser/TypeSpecifier.php

@@ -663,7 +663,24 @@ public function specifyTypesInCondition(
 			$leftTypes = $this->specifyTypesInCondition($scope, $expr->left, $context)->setRootExpr($expr);
 			$rightScope = $scope->filterByFalseyValue($expr->left);
 			$rightTypes = $this->specifyTypesInCondition($rightScope, $expr->right, $context)->setRootExpr($expr);
-			$types = $context->true() ? $leftTypes->normalize($scope)->intersectWith($rightTypes->normalize($rightScope)) : $leftTypes->unionWith($rightTypes);
+
+			if ($context->true()) {
+				if (
+					$scope->getType($expr->left)->isFalse()->yes()
+				) {
+					$types = $rightTypes->normalize($rightScope);
+				} elseif (
+					$scope->getType($expr->left)->isTrue()->yes()
+					|| $scope->getType($expr->right)->isFalse()->yes()
+				) {
+					$types = $leftTypes->normalize($scope);
+				} else {
+					$types = $leftTypes->normalize($scope)->intersectWith($rightTypes->normalize($rightScope));
+				}
+			} else {
+				$types = $leftTypes->unionWith($rightTypes);
+			}
+
 			if ($context->true()) {
 				return (new SpecifiedTypes(
 					$types->getSureTypes(),

tests/PHPStan/Analyser/TypeSpecifierTest.php

@@ -353,7 +353,7 @@ public static function dataCondition(): iterable
 					self::createFunctionCall('is_int', 'foo'),
 					self::createFunctionCall('is_string', 'bar'),
 				),
-				[],
+				['$foo' => 'int'],
 				['$foo' => '~int', '$bar' => '~string'],
 			],
 			[
@@ -652,7 +652,7 @@ public static function dataCondition(): iterable
 			[
 				new Expr\Empty_(new Variable('array')),
 				[
-					'$array' => 'array{}|null',
+					'$array' => 'array{}',
 				],
 				[
 					'$array' => '~0|0.0|\'\'|\'0\'|array{}|false|null',
@@ -664,7 +664,7 @@ public static function dataCondition(): iterable
 					'$array' => '~0|0.0|\'\'|\'0\'|array{}|false|null',
 				],
 				[
-					'$array' => 'array{}|null',
+					'$array' => 'array{}',
 				],
 			],
 			[

tests/PHPStan/Analyser/nsrt/bug-11276.php

@@ -0,0 +1,43 @@
+<?php
+
+namespace Bug11276;
+
+use function PHPStan\Testing\assertType;
+
+function doFoo(int $i, int $j, $arr): void
+{
+	if (false || array_key_exists($i, $arr)) {
+		assertType('non-empty-array', $arr);
+	}
+
+	if (array_key_exists($i, $arr) || false) {
+		assertType('non-empty-array', $arr);
+	}
+
+	if (true || array_key_exists($i, $arr)) {
+		assertType('mixed', $arr);
+	}
+
+	if (array_key_exists($i, $arr) || true) {
+		assertType('mixed', $arr);
+	}
+
+	if (array_key_exists($i, $arr) || array_key_exists($j, $arr)) {
+		assertType('non-empty-array', $arr);
+	}
+
+	if (!array_key_exists($j, $arr)) {
+		if (array_key_exists($i, $arr) || array_key_exists($j, $arr)) {
+			assertType('non-empty-array', $arr);
+		}
+	}
+	if (!array_key_exists($i, $arr)) {
+		if (array_key_exists($i, $arr) || array_key_exists($j, $arr)) {
+			assertType('non-empty-array', $arr);
+		}
+	}
+
+	if (array_key_exists($i, $arr)) {
+		assertType('non-empty-array', $arr);
+	}
+}

tests/PHPStan/Analyser/nsrt/bug-11276b.php

@@ -0,0 +1,20 @@
+<?php // lint >= 8.0
+
+namespace Bug11276b;
+
+use function PHPStan\Testing\assertType;
+
+function doBar($j, array $arr) {
+	$i = 1;
+	if (!array_key_exists($i, $arr)) {
+		if (array_key_exists($i, $arr) || array_key_exists($j, $arr)) {
+			assertType('non-empty-array<mixed~1, mixed>', $arr);
+		}
+	}
+
+	if (!array_key_exists($i, $arr)) {
+		if (array_key_exists($j, $arr) || array_key_exists($i, $arr)) {
+			assertType('non-empty-array<mixed~1, mixed>', $arr);
+		}
+	}
+}

tests/PHPStan/Rules/Arrays/NonexistentOffsetInArrayDimFetchRuleTest.php

@@ -1132,4 +1132,10 @@ public function testBug6209(): void
 		$this->analyse([__DIR__ . '/data/bug-6209.php'], []);
 	}
 
+	public function testBug11276(): void
+	{
+		$this->reportPossiblyNonexistentConstantArrayOffset = true;
+		$this->analyse([__DIR__ . '/data/bug-11276.php'], []);
+	}
+
 }

tests/PHPStan/Rules/Arrays/data/bug-11276.php

@@ -0,0 +1,26 @@
+<?php declare(strict_types = 1);
+
+namespace Bug11276;
+
+class HelloWorld
+{
+	/**
+	 * @param array{from: string, to: string} $expected
+	 */
+	public function testLanguagesMatchingRegex(string $url, ?array $expected): void
+	{
+		preg_match('#\/(?<from>[a-z]{2})-(?<to>[a-z]{1}[a-z0-9]{1})\/#', $url, $matches);
+
+		foreach ($expected as $key => $value) {
+			if ($matches instanceof ArrayAccess || \array_key_exists($key, $matches)) {
+				$matches[$key];
+			}
+		}
+
+		foreach ($expected as $key => $value) {
+			if (\array_key_exists($key, $matches) || $matches instanceof ArrayAccess) {
+				$matches[$key];
+			}
+		}
+	}
+}