Fix phpstan/phpstan#14473: false positive logicalOr.leftAlwaysTrue on repeated builtin function call

When a builtin function with possible side effects (like mysqli_connect())
was assigned with the `or die()` pattern, the conditional expression
mechanism stored a narrowed type for the function call expression in the
scope. On a subsequent assignment of the same function call, this stale
type was retrieved instead of the fresh return type, causing a false
positive "left side of or is always true" error.

The fix skips creating conditional expressions for FuncCall expressions
that refer to builtin functions with possible side effects, since those
function calls can return different values each time and the narrowed
type should not persist across assignments.

Author: phpstan-bot

src/Analyser/ExprHandler/AssignHandler.php

@@ -45,6 +45,7 @@
 use PHPStan\Node\PropertyAssignNode;
 use PHPStan\Node\VariableAssignNode;
 use PHPStan\Php\PhpVersion;
+use PHPStan\Reflection\ReflectionProvider;
 use PHPStan\ShouldNotHappenException;
 use PHPStan\TrinaryLogic;
 use PHPStan\Type\Accessory\AccessoryArrayListType;
@@ -84,6 +85,7 @@ final class AssignHandler implements ExprHandler
 	public function __construct(
 		private TypeSpecifier $typeSpecifier,
 		private PhpVersion $phpVersion,
+		private ReflectionProvider $reflectionProvider,
 	)
 	{
 	}
@@ -861,10 +863,13 @@ private function processSureTypesForConditionalExpressionsAfterAssign(Scope $sco
 				if ($expr->name === $variableName) {
 					continue;
 				}
+			} elseif ($expr instanceof FuncCall) {
+				if ($this->isBuiltinFunctionCallWithPossibleSideEffects($expr, $scope)) {
+					continue;
+				}
 			} elseif (
 				!$expr instanceof PropertyFetch
 				&& !$expr instanceof ArrayDimFetch
-				&& !$expr instanceof FuncCall
 			) {
 				continue;
 			}
@@ -900,10 +905,13 @@ private function processSureNotTypesForConditionalExpressionsAfterAssign(Scope $
 				if ($expr->name === $variableName) {
 					continue;
 				}
+			} elseif ($expr instanceof FuncCall) {
+				if ($this->isBuiltinFunctionCallWithPossibleSideEffects($expr, $scope)) {
+					continue;
+				}
 			} elseif (
 				!$expr instanceof PropertyFetch
 				&& !$expr instanceof ArrayDimFetch
-				&& !$expr instanceof FuncCall
 			) {
 				continue;
 			}
@@ -924,6 +932,21 @@ private function processSureNotTypesForConditionalExpressionsAfterAssign(Scope $
 		return $conditionalExpressions;
 	}
 
+	private function isBuiltinFunctionCallWithPossibleSideEffects(Expr $expr, Scope $scope): bool
+	{
+		if (!$expr instanceof FuncCall || !$expr->name instanceof Name) {
+			return false;
+		}
+
+		if (!$this->reflectionProvider->hasFunction($expr->name, $scope)) {
+			return false;
+		}
+
+		$functionReflection = $this->reflectionProvider->getFunction($expr->name, $scope);
+
+		return $functionReflection->isBuiltin() && !$functionReflection->hasSideEffects()->no();
+	}
+
 	/**
 	 * @param list<ArrayDimFetch> $dimFetchStack
 	 */

tests/PHPStan/Rules/Comparison/BooleanOrConstantConditionRuleTest.php

@@ -384,4 +384,11 @@ public function testBug10305(): void
 		]);
 	}
 
+	public function testBug14473(): void
+	{
+		$this->treatPhpDocTypesAsCertain = true;
+
+		$this->analyse([__DIR__ . '/data/bug-14473.php'], []);
+	}
+
 }

tests/PHPStan/Rules/Comparison/data/bug-14473.php

@@ -0,0 +1,27 @@
+<?php declare(strict_types = 1);
+
+namespace Bug14473;
+
+$link = mysqli_connect('host', 'user', 'pass', 'database') or die('Could not connect: ' . mysqli_connect_error());
+
+// (assume long-running code that can cause the connection to time out)
+
+$link = mysqli_connect('host', 'user', 'pass', 'database') or die('Could not reconnect: ' . mysqli_connect_error());
+
+// okay, so let's make certain that the connection is closed
+mysqli_close($link);
+
+$link = mysqli_connect('host', 'user', 'pass', 'database') or die('Could not reconnect: ' . mysqli_connect_error());
+
+// close it and destroy the variable
+mysqli_close($link);
+unset($link);
+
+$link = mysqli_connect('host', 'user', 'pass', 'database') or die('Could not reconnect: ' . mysqli_connect_error());
+
+// close, destroy ...
+mysqli_close($link);
+unset($link);
+
+// ... and assign to a different variable
+$newLink = mysqli_connect('host', 'user', 'pass', 'database') or die('Could not reconnect: ' . mysqli_connect_error());