Fixes calculateRangesAfterReplacements crash when Replacements is empty.

Reviewers: klimek, djasper

Subscribers: cfe-commits, klimek

Differential Revision: https://reviews.llvm.org/D23264

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@278004 91177308-0d34-0410-b5e6-96231b3b80d8

Author: Eric Liu

Diff for: lib/Tooling/Core/Replacement.cpp

@@ -361,6 +361,8 @@ calculateRangesAfterReplacements(const Replacements &Replaces,
   //   - Merge with \p Replaces.
   //   - The new ranges will be the affected ranges of the merged replacements.
   auto MergedRanges = combineAndSortRanges(Ranges);
+  if (Replaces.empty())
+    return MergedRanges;
   tooling::Replacements FakeReplaces;
   for (const auto &R : MergedRanges) {
     auto Err = FakeReplaces.add(Replacement(Replaces.begin()->getFilePath(),

Diff for: unittests/Tooling/RefactoringTest.cpp

@@ -506,6 +506,13 @@ TEST(Range, CalculateRangesOfReplacements) {
   EXPECT_TRUE(Ranges[1].getLength() == 22);
 }
 
+TEST(Range, RangesAfterEmptyReplacements) {
+  std::vector<Range> Ranges = {Range(5, 6), Range(10, 5)};
+  Replacements Replaces;
+  std::vector<Range> Expected = {Range(5, 10)};
+  EXPECT_EQ(Expected, calculateRangesAfterReplacements(Replaces, Ranges));
+}
+
 TEST(Range, RangesAfterReplacements) {
   std::vector<Range> Ranges = {Range(5, 2), Range(10, 5)};
   Replacements Replaces = toReplacements({Replacement("foo", 0, 2, "1234")});