Fix narrowing of superglobals

Author: ondrejmirtes

src/Analyser/MutatingScope.php

@@ -4833,6 +4833,8 @@ private function createConditionalExpressions(
 	private function mergeVariableHolders(array $ourVariableTypeHolders, array $theirVariableTypeHolders): array
 	{
 		$intersectedVariableTypeHolders = [];
+		$globalVariableCallback = fn (Node $node) => $node instanceof Variable && is_string($node->name) && $this->isGlobalVariable($node->name);
+		$nodeFinder = new NodeFinder();
 		foreach ($ourVariableTypeHolders as $exprString => $variableTypeHolder) {
 			if (isset($theirVariableTypeHolders[$exprString])) {
 				if ($variableTypeHolder === $theirVariableTypeHolders[$exprString]) {
@@ -4842,6 +4844,11 @@ private function mergeVariableHolders(array $ourVariableTypeHolders, array $thei
 
 				$intersectedVariableTypeHolders[$exprString] = $variableTypeHolder->and($theirVariableTypeHolders[$exprString]);
 			} else {
+				$expr = $variableTypeHolder->getExpr();
+				if ($nodeFinder->findFirst($expr, $globalVariableCallback) !== null) {
+					continue;
+				}
+
 				$intersectedVariableTypeHolders[$exprString] = ExpressionTypeHolder::createMaybe($variableTypeHolder->getExpr(), $variableTypeHolder->getType());
 			}
 		}
@@ -4851,6 +4858,11 @@ private function mergeVariableHolders(array $ourVariableTypeHolders, array $thei
 				continue;
 			}
 
+			$expr = $variableTypeHolder->getExpr();
+			if ($nodeFinder->findFirst($expr, $globalVariableCallback) !== null) {
+				continue;
+			}
+
 			$intersectedVariableTypeHolders[$exprString] = ExpressionTypeHolder::createMaybe($variableTypeHolder->getExpr(), $variableTypeHolder->getType());
 		}
 

tests/PHPStan/Analyser/nsrt/superglobals.php

@@ -0,0 +1,69 @@
+<?php declare(strict_types=1);
+
+namespace Superglobals;
+
+use function PHPStan\Testing\assertNativeType;
+use function PHPStan\Testing\assertType;
+
+class Superglobals
+{
+
+	public function originalTypes(): void
+	{
+		assertType('array<mixed>', $GLOBALS);
+		assertType('array<mixed>', $_SERVER);
+		assertType('array<mixed>', $_GET);
+		assertType('array<mixed>', $_POST);
+		assertType('array<mixed>', $_FILES);
+		assertType('array<mixed>', $_COOKIE);
+		assertType('array<mixed>', $_SESSION);
+		assertType('array<mixed>', $_REQUEST);
+		assertType('array<mixed>', $_ENV);
+	}
+
+	public function canBeOverwritten(): void
+	{
+		$GLOBALS = [];
+		assertType('array{}', $GLOBALS);
+		assertNativeType('array{}', $GLOBALS);
+	}
+
+	public function canBePartlyOverwritten(): void
+	{
+		$GLOBALS['foo'] = 'foo';
+		assertType("non-empty-array&hasOffsetValue('foo', 'foo')", $GLOBALS);
+		assertNativeType("non-empty-array&hasOffsetValue('foo', 'foo')", $GLOBALS);
+	}
+
+	public function canBeNarrowed(): void
+	{
+		if (isset($GLOBALS['foo'])) {
+			assertType("non-empty-array&hasOffsetValue('foo', mixed~null)", $GLOBALS);
+			assertNativeType("non-empty-array<mixed>&hasOffset('foo')", $GLOBALS); // https://github.com/phpstan/phpstan/issues/8395
+		} else {
+			assertType('array<mixed>', $GLOBALS);
+			assertNativeType('array<mixed>', $GLOBALS);
+		}
+		assertType('array<mixed>', $GLOBALS);
+		assertNativeType('array<mixed>', $GLOBALS);
+	}
+
+}
+
+function functionScope() {
+	assertType('array<mixed>', $GLOBALS);
+	assertNativeType('array<mixed>', $GLOBALS);
+}
+
+assertType('array<mixed>', $GLOBALS);
+assertNativeType('array<mixed>', $GLOBALS);
+
+function badNarrowing() {
+	if (empty($_GET['id'])) {
+		echo "b";
+	} else {
+		echo "b";
+	}
+	assertType('array<mixed>', $_GET);
+	assertType('mixed', $_GET['id']);
+};

tests/PHPStan/Rules/Comparison/StrictComparisonOfDifferentTypesRuleTest.php

@@ -1001,4 +1001,9 @@ public function testHashing(): void
 		]);
 	}
 
+	public function testBug12772(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-12772.php'], []);
+	}
+
 }

tests/PHPStan/Rules/Comparison/data/bug-12772.php

@@ -0,0 +1,17 @@
+<?php declare(strict_types = 1);
+
+namespace Bug12772;
+
+class HelloWorld
+{
+	public function sayHello(DateTimeImutable $date): void
+	{
+		foreach ($tables as $table) {
+
+			// If view exists, and 'add drop view' is selected: Drop it!
+			if ($_POST['what'] !== 'nocopy' && isset($_POST['drop_if_exists']) && $_POST['drop_if_exists'] === 'true') {
+
+			}
+		}
+	}
+}

tests/PHPStan/Rules/Variables/IssetRuleTest.php

@@ -473,4 +473,11 @@ public function testBug9328(): void
 		$this->analyse([__DIR__ . '/data/bug-9328.php'], []);
 	}
 
+	public function testBug12771(): void
+	{
+		$this->treatPhpDocTypesAsCertain = true;
+
+		$this->analyse([__DIR__ . '/data/bug-12771.php'], []);
+	}
+
 }

tests/PHPStan/Rules/Variables/data/bug-12771.php

@@ -0,0 +1,25 @@
+<?php declare(strict_types=1);
+
+namespace Bug12771;
+
+final class ErrorReportController
+{
+
+	public function __invoke(ServerRequest $request)
+	{
+		if (
+			isset($_SESSION['prev_error_subm_time'], $_SESSION['error_subm_count'])
+			&& $_SESSION['error_subm_count'] >= 3
+			&& ($_SESSION['prev_error_subm_time'] - time()) <= 3000
+		) {
+			$_SESSION['error_subm_count'] = 0;
+			$_SESSION['prev_errors'] = '';
+		} else {
+			$_SESSION['prev_error_subm_time'] = time();
+			$_SESSION['error_subm_count'] = isset($_SESSION['error_subm_count'])
+				? $_SESSION['error_subm_count'] + 1
+				: 0;
+		}
+
+	}
+}