Fix #10315: False positive: Dead catch

src/PhpDoc/PhpDocInheritanceResolver.php

@@ -142,7 +142,45 @@ public function resolvePhpDocForMethod(
 			return $this->resolveMethodPhpDocFromParentClass($traitMethod, $resolvedPhpDocBlock, $declaringClass, $trait, $currentResolvedPhpDoc, $currentPositionalParameterNames);
 		}
 
-		return $currentResolvedPhpDoc;
+		$result = $currentResolvedPhpDoc;
+
+		// Inherit @throws from non-abstract trait methods
+		if ($result === null || $result->getThrowsTag() === null) {
+			foreach ($declaringClass->getTraits() as $trait) {
+				if (!$trait->hasNativeMethod($methodName)) {
+					continue;
+				}
+
+				$traitMethod = $trait->getNativeMethod($methodName);
+				if ($traitMethod->getDocComment() === null) {
+					continue;
+				}
+				if ($declaringClass->getFileName() === null) {
+					continue;
+				}
+
+				$traitResolvedPhpDoc = $this->fileTypeMapper->getResolvedPhpDoc(
+					$declaringClass->getFileName(),
+					$declaringClass->getName(),
+					$trait->getName(),
+					$methodName,
+					$traitMethod->getDocComment(),
+				);
+
+				$throwsTag = $traitResolvedPhpDoc->getThrowsTag();
+				if ($throwsTag === null) {
+					continue;
+				}
+
+				if ($result === null) {
+					$result = ResolvedPhpDocBlock::createEmpty();
+				}
+				$result = $result->withThrowsTag($throwsTag);
+				break;
+			}
+		}
+
+		return $result;
 	}
 
 	/**

src/PhpDoc/ResolvedPhpDocBlock.php

@@ -621,6 +621,14 @@ public function getThrowsTag(): ?ThrowsTag
 		return $this->throwsTag;
 	}
 
+	public function withThrowsTag(ThrowsTag $throwsTag): self
+	{
+		$result = clone $this;
+		$result->throwsTag = $throwsTag;
+
+		return $result;
+	}
+
 	/**
 	 * @return array<MixinTag>
 	 */

tests/PHPStan/Rules/Exceptions/CatchWithUnthrownExceptionRuleStubsTest.php

@@ -36,6 +36,11 @@ public function testRule(): void
 		]);
 	}
 
+	public function testBug10315(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-10315.php'], []);
+	}
+
 	public static function getAdditionalConfigFiles(): array
 	{
 		return [

tests/PHPStan/Rules/Exceptions/data/bug-10315.php

@@ -0,0 +1,62 @@
+<?php // lint >= 8.0
+
+declare(strict_types = 1);
+
+namespace Bug10315;
+
+class MyException extends \RuntimeException
+{
+}
+
+trait DriverPoolAbstractTrait
+{
+	/**
+	 * @throws MyException
+	 */
+	protected function driverReadMultiple(): array
+	{
+		throw new MyException();
+	}
+}
+
+trait CacheItemPoolTrait
+{
+	public function getItems(): array
+	{
+		try {
+			$result = $this->driverReadMultiple();
+		} catch (MyException) {
+			$result = [];
+		}
+
+		return $result;
+	}
+}
+
+// Scenario A: base uses DriverPoolAbstractTrait, child uses CacheItemPoolTrait and overrides
+abstract class AbstractPoolA
+{
+	use DriverPoolAbstractTrait;
+}
+
+class RedisDriverA extends AbstractPoolA
+{
+	use CacheItemPoolTrait;
+
+	protected function driverReadMultiple(): array
+	{
+		return ['key' => 'value'];
+	}
+}
+
+// Scenario B: class uses both traits and overrides the method directly
+class DirectDriverB
+{
+	use DriverPoolAbstractTrait;
+	use CacheItemPoolTrait;
+
+	protected function driverReadMultiple(): array
+	{
+		return ['key' => 'value'];
+	}
+}