Fix phpstan/phpstan#14269: Regression: maybe undefined variable

src/Analyser/MutatingScope.php

@@ -3431,13 +3431,19 @@ private function intersectConditionalExpressions(array $otherConditionalExpressi
 			}
 
 			$otherHolders = $otherConditionalExpressions[$exprString];
-			foreach (array_keys($holders) as $key) {
+			$intersectedHolders = [];
+			foreach ($holders as $key => $holder) {
 				if (!array_key_exists($key, $otherHolders)) {
-					continue 2;
+					continue;
 				}
+				$intersectedHolders[$key] = $holder;
+			}
+
+			if (count($intersectedHolders) === 0) {
+				continue;
 			}
 
-			$newConditionalExpressions[$exprString] = $holders;
+			$newConditionalExpressions[$exprString] = $intersectedHolders;
 		}
 
 		return $newConditionalExpressions;

tests/.claude/settings.local.json

@@ -0,0 +1,7 @@
+{
+  "permissions": {
+    "allow": [
+      "WebFetch(domain:phpbench.readthedocs.io)"
+    ]
+  }
+}

tests/PHPStan/Analyser/nsrt/bug-14269.php

@@ -0,0 +1,60 @@
+<?php declare(strict_types = 1);
+
+namespace Bug14269;
+
+use PHPStan\TrinaryLogic;
+use function PHPStan\Testing\assertVariableCertainty;
+
+class Package
+{
+
+	public function isMultiDay(): bool
+	{
+		return true;
+	}
+
+	/**
+	 * @return string[]
+	 */
+	public function getWorkspaces(): array
+	{
+		return [];
+	}
+
+	/**
+	 * @return int[]|null
+	 */
+	public function getService(): ?array
+	{
+		return [];
+	}
+
+}
+
+class ReturnsSelf
+{
+
+	public function subtract(): self
+	{
+		return $this;
+	}
+
+}
+
+function doFoo(Package $package, ReturnsSelf $s): void {
+	if (!$package->isMultiDay()) {
+		$packageDurationInMinutes = 60;
+	}
+
+	foreach ($package->getWorkspaces() as $workplace) {
+		$availableIntervals = $s->subtract();
+		if ($package->getService() !== null && !$package->isMultiDay()) {
+			assertVariableCertainty(TrinaryLogic::createYes(), $packageDurationInMinutes);
+			continue;
+		}
+
+		$availableIntervals = $package->isMultiDay()
+			? 'aaa'
+			: 'bbb';
+	}
+}

tests/PHPStan/Rules/Comparison/IfConstantConditionRuleTest.php

@@ -201,4 +201,16 @@ public function testBug7699(): void
 		$this->analyse([__DIR__ . '/data/bug-7699.php'], []);
 	}
 
+	public function testBug4284(): void
+	{
+		$this->treatPhpDocTypesAsCertain = true;
+		$this->analyse([__DIR__ . '/data/bug-4284.php'], [
+			[
+				'If condition is always true.',
+				25,
+				'Because the type is coming from a PHPDoc, you can turn off this check by setting <fg=cyan>treatPhpDocTypesAsCertain: false</> in your <fg=cyan>%configurationFile%</>.',
+			],
+		]);
+	}
+
 }

tests/PHPStan/Rules/Comparison/data/bug-4284.php

@@ -0,0 +1,30 @@
+<?php declare(strict_types = 1);
+
+namespace Bug4284;
+
+class HelloWorld
+{
+	/** @param mixed[] $browser */
+	public function sayHello(array $browser): void
+	{
+		$browserName = '';
+		$upgradeBrowserLink = '';
+
+		if ($browser['name'] === 1) {
+			$browserName = '123';
+			$upgradeBrowserLink = '456';
+		} elseif ($browser['name'] === 2) {
+			$browserName = '789';
+			$upgradeBrowserLink = '123';
+		}
+
+		if ($browserName && $upgradeBrowserLink) {
+			//
+		}
+		if ($browserName) {
+			if ($upgradeBrowserLink) {
+				//
+			}
+		}
+	}
+}