1 files changed, 56 insertions, 0 deletions
diff --git a/clang/unittests/Basic/VirtualFileSystemTest.cpp b/clang/unittests/Basic/VirtualFileSystemTest.cpp
index 992f0d8..a33f2b1 100644
--- a/clang/unittests/Basic/VirtualFileSystemTest.cpp
+++ b/clang/unittests/Basic/VirtualFileSystemTest.cpp
@@ -8,7 +8,9 @@
 //===----------------------------------------------------------------------===//
 
 #include "clang/Basic/VirtualFileSystem.h"
+#include "llvm/ADT/Triple.h"
 #include "llvm/Support/Errc.h"
+#include "llvm/Support/Host.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/Path.h"
 #include "llvm/Support/SourceMgr.h"
@@ -680,6 +682,12 @@ public:
     VersionPlusContent += Content.slice(Content.find('{') + 1, StringRef::npos);
     return getFromYAMLRawString(VersionPlusContent, ExternalFS);
   }
+
+  // This is intended as a "XFAIL" for windows hosts.
+  bool supportsSameDirMultipleYAMLEntries() {
+    Triple Host(Triple::normalize(sys::getProcessTriple()));
+    return !Host.isOSWindows();
+  }
 };
 
 TEST_F(VFSFromYAMLTest, BasicVFSFromYAML) {
@@ -1066,3 +1074,51 @@ TEST_F(VFSFromYAMLTest, DirectoryIteration) {
   checkContents(O->dir_begin("//root/foo/bar", EC),
                 {"//root/foo/bar/a", "//root/foo/bar/b"});
 }
+
+TEST_F(VFSFromYAMLTest, DirectoryIterationSameDirMultipleEntries) {
+  // https://llvm.org/bugs/show_bug.cgi?id=27725
+  if (!supportsSameDirMultipleYAMLEntries())
+    return;
+
+  IntrusiveRefCntPtr<DummyFileSystem> Lower(new DummyFileSystem());
+  Lower->addDirectory("//root/zab");
+  Lower->addDirectory("//root/baz");
+  Lower->addRegularFile("//root/zab/a");
+  Lower->addRegularFile("//root/zab/b");
+  IntrusiveRefCntPtr<vfs::FileSystem> FS = getFromYAMLString(
+      "{ 'use-external-names': false,\n"
+      "  'roots': [\n"
+      "{\n"
+      "  'type': 'directory',\n"
+      "  'name': '//root/baz/',\n"
+      "  'contents': [ {\n"
+      "                  'type': 'file',\n"
+      "                  'name': 'x',\n"
+      "                  'external-contents': '//root/zab/a'\n"
+      "                }\n"
+      "              ]\n"
+      "},\n"
+      "{\n"
+      "  'type': 'directory',\n"
+      "  'name': '//root/baz/',\n"
+      "  'contents': [ {\n"
+      "                  'type': 'file',\n"
+      "                  'name': 'y',\n"
+      "                  'external-contents': '//root/zab/b'\n"
+      "                }\n"
+      "              ]\n"
+      "}\n"
+      "]\n"
+      "}",
+      Lower);
+  ASSERT_TRUE(FS.get() != nullptr);
+
+  IntrusiveRefCntPtr<vfs::OverlayFileSystem> O(
+      new vfs::OverlayFileSystem(Lower));
+  O->pushOverlay(FS);
+
+  std::error_code EC;
+
+  checkContents(O->dir_begin("//root/baz/", EC),
+                {"//root/baz/x", "//root/baz/y"});
+}