Fix too early inference

Author: VincentLanglet

Diff for: src/Analyser/MutatingScope.php

@@ -1129,9 +1129,6 @@ private function resolveType(string $exprString, Expr $node): Type
 				}
 
 				$resultType = $this->initializerExprTypeResolver->resolveConcatType($resultType, $partType);
-				if (count($resultType->getConstantStrings()) === 0) {
-					return $resultType;
-				}
 			}
 
 			return $resultType ?? new ConstantStringType('');

Diff for: tests/PHPStan/Rules/Comparison/MatchExpressionRuleTest.php

@@ -599,4 +599,13 @@ public function testBug9436(): void
 		$this->analyse([__DIR__ . '/data/bug-9436.php'], []);
 	}
 
+	public function testBug11852(): void
+	{
+		if (PHP_VERSION_ID < 80000) {
+			$this->markTestSkipped('Test requires PHP 8.0.');
+		}
+
+		$this->analyse([__DIR__ . '/data/bug-11852.php'], []);
+	}
+
 }

Diff for: tests/PHPStan/Rules/Comparison/data/bug-11852.php

@@ -0,0 +1,13 @@
+<?php // lint >= 8.0
+
+namespace Bug11852;
+
+function sayHello(int $type, string $activity): int
+{
+	return match("$type:$activity") {
+		'159:Work' => 12,
+		'159:education' => 19,
+
+		default => throw new \InvalidArgumentException("unknown values $type:$activity"),
+	};
+}