Merge branch 'en/dirty-merge-fixes'

The recursive merge strategy did not properly ensure there was no
change between HEAD and the index before performing its operation,
which has been corrected.

* en/dirty-merge-fixes:
  merge: fix misleading pre-merge check documentation
  merge-recursive: enforce rule that index matches head before merging
  t6044: add more testcases with staged changes before a merge is invoked
  merge-recursive: fix assumption that head tree being merged is HEAD
  merge-recursive: make sure when we say we abort that we actually abort
  t6044: add a testcase for index matching head, when head doesn't match HEAD
  t6044: verify that merges expected to abort actually abort
  index_has_changes(): avoid assuming operating on the_index
  read-cache.c: move index_has_changes() from merge.c

1 files changed, 3 insertions, 3 deletions

diff --git a/Documentation/git-merge.txt b/Documentation/git-merge.txt
index 537dca7faa..eb36837f86 100644
--- a/Documentation/git-merge.txt
+++ b/Documentation/git-merge.txt
@@ -130,9 +130,9 @@ merge' may need to update.
 
 To avoid recording unrelated changes in the merge commit,
 'git pull' and 'git merge' will also abort if there are any changes
-registered in the index relative to the `HEAD` commit.  (One
-exception is when the changed index entries are in the state that
-would result from the merge already.)
+registered in the index relative to the `HEAD` commit.  (Special
+narrow exceptions to this rule may exist depending on which merge
+strategy is in use, but generally, the index must match HEAD.)
 
 If all named commits are already ancestors of `HEAD`, 'git merge'
 will exit early with the message "Already up to date."