Don't treat .foo as two path components in path::iterators

We were treating '/.foo' as ['/', '.', 'foo'] instead of ['/', '.foo'],
which lead to insanity.  Same for '..'.

llvm-svn: 231727
diff --git a/llvm/unittests/Support/Path.cpp b/llvm/unittests/Support/Path.cpp
index 00af989..479812c 100644
--- a/llvm/unittests/Support/Path.cpp
+++ b/llvm/unittests/Support/Path.cpp
@@ -168,6 +168,26 @@
   }
 }
 
+TEST(Support, RelativePathDotIterator) {
+  SmallString<64> Path(StringRef(".c/.d/../."));
+  typedef SmallVector<StringRef, 4> PathComponents;
+  PathComponents ExpectedPathComponents;
+  PathComponents ActualPathComponents;
+
+  StringRef(Path).split(ExpectedPathComponents, "/");
+
+  for (path::const_iterator I = path::begin(Path), E = path::end(Path); I != E;
+       ++I) {
+    ActualPathComponents.push_back(*I);
+  }
+
+  ASSERT_EQ(ExpectedPathComponents.size(), ActualPathComponents.size());
+
+  for (size_t i = 0; i <ExpectedPathComponents.size(); ++i) {
+    EXPECT_EQ(ExpectedPathComponents[i].str(), ActualPathComponents[i].str());
+  }
+}
+
 TEST(Support, AbsolutePathIterator) {
   SmallString<64> Path(StringRef("/c/d/e/foo.txt"));
   typedef SmallVector<StringRef, 4> PathComponents;
@@ -191,6 +211,29 @@
   }
 }
 
+TEST(Support, AbsolutePathDotIterator) {
+  SmallString<64> Path(StringRef("/.c/.d/../."));
+  typedef SmallVector<StringRef, 4> PathComponents;
+  PathComponents ExpectedPathComponents;
+  PathComponents ActualPathComponents;
+
+  StringRef(Path).split(ExpectedPathComponents, "/");
+
+  // The root path will also be a component when iterating
+  ExpectedPathComponents[0] = "/";
+
+  for (path::const_iterator I = path::begin(Path), E = path::end(Path); I != E;
+       ++I) {
+    ActualPathComponents.push_back(*I);
+  }
+
+  ASSERT_EQ(ExpectedPathComponents.size(), ActualPathComponents.size());
+
+  for (size_t i = 0; i <ExpectedPathComponents.size(); ++i) {
+    EXPECT_EQ(ExpectedPathComponents[i].str(), ActualPathComponents[i].str());
+  }
+}
+
 #ifdef LLVM_ON_WIN32
 TEST(Support, AbsolutePathIteratorWin32) {
   SmallString<64> Path(StringRef("c:\\c\\e\\foo.txt"));