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

* 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 ab4077f272919fb47e3c5f179dc42fc9baad68bb,9567d60ba2d46e5f30cb6d954a74db8bcb5e9ee5..581f494aee01f97bb87a94dbfd1fba4d14afaa69
--- 1/builtin/merge.c
--- 2/builtin/merge.c
+++ b/builtin/merge.c
@@@ -901,8 -905,8 +903,8 @@@ 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