Fix pretty printing of incorrectly formatted closures with a signature and multiple statements

Author: stackotter

Sources/SwiftFormatPrettyPrint/TokenStreamCreator.swift

@@ -1073,7 +1073,7 @@ fileprivate final class TokenStreamCreator: SyntaxVisitor {
 
   override func visit(_ node: ClosureExprSyntax) -> SyntaxVisitorContinueKind {
     let newlineBehavior: NewlineBehavior
-    if forcedBreakingClosures.remove(node.id) != nil {
+    if forcedBreakingClosures.remove(node.id) != nil || node.statements.count > 1 {
       newlineBehavior = .soft
     } else {
       newlineBehavior = .elective

Tests/SwiftFormatPrettyPrintTests/ClosureExprTests.swift

@@ -516,4 +516,24 @@ final class ClosureExprTests: PrettyPrintTestCase {
 
     assertPrettyPrintEqual(input: input, expected: expected, linelength: 40)
   }
+
+  func testClosureWithSignatureAndMultipleStatements() {
+    let input =
+      """
+      { a in a + 1
+        a + 2
+      }
+      """
+
+    let expected =
+      """
+      { a in
+        a + 1
+        a + 2
+      }
+
+      """
+
+    assertPrettyPrintEqual(input: input, expected: expected, linelength: 40)
+  }
 }