ctest_update: Support Git upstream branch rewrites

Use 'git fetch' followed by 'git reset' to update the source tree.  This
is better than 'git pull' because it can handle a rewritten upstream
branch and does not leave local modifications.  After fetch, parse
FETCH_HEAD to find the merge head that 'git pull' would choose to track
the upstream branch.  Then reset to the selected head.

In the normal fast-forward case the behavior remains unchanged.
However, now local modifications and commits will be erased, and
upstream rewrites are handled smoothly.  This ensures that the upstream
branch is tested as expected.

1 files changed, 1 insertions, 1 deletions

diff --git a/Source/CTest/cmCTestGIT.h b/Source/CTest/cmCTestGIT.h
index bdb2c62..d8681fe 100644
--- a/Source/CTest/cmCTestGIT.h
+++ b/Source/CTest/cmCTestGIT.h
@@ -32,7 +32,7 @@ private:
   virtual void NoteNewRevision();
   virtual bool UpdateImpl();
 
-  bool UpdateByPull();
+  bool UpdateByFetchAndReset();
   bool UpdateByCustom(std::string const& custom);
   bool UpdateInternal();