Index: clang/test/Format/macro.cpp
===================================================================
--- /dev/null
+++ clang/test/Format/macro.cpp
@@ -0,0 +1,5 @@
+// RUN: clang-format -style="{AllowShortCaseLabelsOnASingleLine: true}" %s > %t
+// RUN: diff %s %t
+#define X                                                                      \
+  case 0: break;
+#include "f"