Merge branch 'nd/maint-autofix-tag-in-head'

* nd/maint-autofix-tag-in-head:
  Accept tags in HEAD or MERGE_HEAD
  merge: remove global variable head[]
  merge: use return value of resolve_ref() to determine if HEAD is invalid
  merge: keep stash[] a local variable

Conflicts:
	builtin/merge.c

diff --cc builtin/commit.c
Simple merge

diff --cc builtin/merge.c
index ee56974371fa9224ecb4b8203fb1356b6cf6e156,9567d60ba2d46e5f30cb6d954a74db8bcb5e9ee5..7d593097dea987e580d1e79f010faf23c1f98fb0
--- 1/builtin/merge.c
--- 2/builtin/merge.c
+++ b/builtin/merge.c
@@@ -911,8 -905,8 +913,8 @@@ static int finish_automerge(struct comm
        strbuf_addch(&merge_msg, '\n');
        run_prepare_commit_msg();
        commit_tree(merge_msg.buf, result_tree, parents, result_commit, NULL);
 -      strbuf_addf(&buf, "Merge made by %s.", wt_strategy);
 +      strbuf_addf(&buf, "Merge made by the '%s' strategy.", wt_strategy);
-       finish(result_commit, buf.buf);
+       finish(head, result_commit, buf.buf);
        strbuf_release(&buf);
        drop_save();
        return 0;

diff --cc commit.c
Simple merge

diff --cc commit.h
Simple merge

diff --cc http-push.c
Simple merge

diff --cc revision.c
Simple merge