[PATCH 0/2] report lock error in write_index

In the repo_refresh_and_write_index of read-cache.c, we return -1 to
indicate that writing the index to disk failed.
However, callers do not use this information. Commands such as stash print
  "could not write index"
and then exit, which does not help to discover the exact problem.

We can let repo_hold_locked_index print the error message if the locking failed.

The second commit is to provide a more consistent error message in various commands when writing index failed. Currently, there are 10 uses of "could not write index", two uses of "unable to write index file" and "Unable to write index.". Change them to the most used "could not write index".

Han Young (2):
  read-cache: report lock error when refreshing index
  read-cache: unify write index error message

 builtin/am.c         | 2 +-
 builtin/commit.c     | 2 +-
 builtin/merge.c      | 2 +-
 merge-ort-wrappers.c | 2 +-
 read-cache.c         | 2 +-
 5 files changed, 5 insertions(+), 5 deletions(-)