Fix offset access + key-of template type combination

src/Type/Generic/TemplateKeyOfType.php

@@ -46,6 +46,24 @@ public function traverse(callable $cb): Type
 		return $this;
 	}
 
+	protected function getResult(): Type
+	{
+		$result = $this->getBound()->getResult();
+
+		$type = TemplateTypeFactory::create(
+			$this->getScope(),
+			$this->getName(),
+			$result,
+			$this->getVariance(),
+		);
+
+		if ($this->isArgument()) {
+			$type = TemplateTypeHelper::toArgument($type);
+		}
+
+		return $type;
+	}
+
 	protected function shouldGeneralizeInferredType(): bool
 	{
 		return false;

src/Type/Generic/TemplateTypeTrait.php

@@ -249,8 +249,14 @@ public function inferTemplateTypes(Type $receivedType): TemplateTypeMap
 		$map = $this->getBound()->inferTemplateTypes($receivedType);
 		$resolvedBound = TypeUtils::resolveLateResolvableTypes(TemplateTypeHelper::resolveTemplateTypes($this->getBound(), $map));
 		if ($resolvedBound->isSuperTypeOf($receivedType)->yes()) {
+			if ($this->shouldGeneralizeInferredType()) {
+				$generalizedType = $receivedType->generalize(GeneralizePrecision::templateArgument());
+				if ($resolvedBound->isSuperTypeOf($generalizedType)->yes()) {
+					$receivedType = $generalizedType;
+				}
+			}
 			return (new TemplateTypeMap([
-				$this->name => $this->shouldGeneralizeInferredType() ? $receivedType->generalize(GeneralizePrecision::templateArgument()) : $receivedType,
+				$this->name => $receivedType,
 			]))->union($map);
 		}
 

tests/PHPStan/Analyser/AnalyserIntegrationTest.php

@@ -806,7 +806,7 @@ public function testBug7094(): void
 		$this->assertSame('Return type of call to method Bug7094\Foo::getAttribute() contains unresolvable type.', $errors[4]->getMessage());
 		$this->assertSame(79, $errors[4]->getLine());
 
-		$this->assertSame('Parameter #1 $attr of method Bug7094\Foo::setAttributes() expects array{foo?: string, bar?: 5|6|7, baz?: bool}, non-empty-array<string, 5|6|7|bool|string> given.', $errors[5]->getMessage());
+		$this->assertSame('Parameter #1 $attr of method Bug7094\Foo::setAttributes() expects array{foo?: string, bar?: 5|6|7, baz?: bool}, non-empty-array<K of string, 5|6|7|bool|string> given.', $errors[5]->getMessage());
 		$this->assertSame(29, $errors[5]->getLine());
 	}
 

tests/PHPStan/Analyser/NodeScopeResolverTest.php

@@ -977,6 +977,7 @@ public function dataFileAsserts(): iterable
 		}
 
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/closure-argument-type.php');
+		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-7788.php');
 	}
 
 	/**

tests/PHPStan/Analyser/data/bug-7788.php

@@ -0,0 +1,34 @@
+<?php
+
+namespace Bug7788;
+
+use function PHPStan\Testing\assertType;
+
+/**
+ * @template T of array<string, mixed>
+ */
+final class Props
+{
+    /**
+     * @param T $props
+     */
+    public function __construct(private array $props = [])
+    {
+    }
+
+	/**
+	 * @template K of key-of<T>
+	 * @template TDefault
+	 * @param K $propKey
+	 * @param TDefault $default
+	 * @return T[K]|TDefault
+	 */
+	public function getProp(string $propKey, mixed $default = null): mixed
+    {
+        return $this->props[$propKey] ?? $default;
+    }
+}
+
+function () {
+	assertType('int', (new Props(['title' => 'test', 'value' => 30]))->getProp('value', 0));
+};