[Path] Set FD to -1 in moved-from TempFile

When moving a temp file, explicitly set the file descriptor to -1 so we
can never accidentally close the moved-from TempFile.

Differential revision: https://reviews.llvm.org/D63087

llvm-svn: 363083

Author: JDevlieghere

llvm/lib/Support/Path.cpp

@@ -1125,6 +1125,7 @@ TempFile &TempFile::operator=(TempFile &&Other) {
   TmpName = std::move(Other.TmpName);
   FD = Other.FD;
   Other.Done = true;
+  Other.FD = -1;
   return *this;
 }
 

llvm/unittests/Support/Path.cpp

@@ -578,6 +578,7 @@ TEST_F(FileSystemTest, TempFileKeepDiscard) {
   auto TempFileOrError = fs::TempFile::create(TestDirectory + "/test-%%%%");
   ASSERT_TRUE((bool)TempFileOrError);
   fs::TempFile File = std::move(*TempFileOrError);
+  ASSERT_EQ(-1, TempFileOrError->FD);
   ASSERT_FALSE((bool)File.keep(TestDirectory + "/keep"));
   ASSERT_FALSE((bool)File.discard());
   ASSERT_TRUE(fs::exists(TestDirectory + "/keep"));
@@ -589,6 +590,7 @@ TEST_F(FileSystemTest, TempFileDiscardDiscard) {
   auto TempFileOrError = fs::TempFile::create(TestDirectory + "/test-%%%%");
   ASSERT_TRUE((bool)TempFileOrError);
   fs::TempFile File = std::move(*TempFileOrError);
+  ASSERT_EQ(-1, TempFileOrError->FD);
   ASSERT_FALSE((bool)File.discard());
   ASSERT_FALSE((bool)File.discard());
   ASSERT_FALSE(fs::exists(TestDirectory + "/keep"));