Merge branch 'jc/unresolve-removal'

"checkout --merge -- path" and "update-index --unresolve path" did
not resurrect conflicted state that was resolved to remove path,
but now they do.

* jc/unresolve-removal:
  checkout: allow "checkout -m path" to unmerge removed paths
  checkout/restore: add basic tests for --merge
  checkout/restore: refuse unmerging paths unless checking out of the index
  update-index: remove stale fallback code for "--unresolve"
  update-index: use unmerge_index_entry() to support removal
  resolve-undo: allow resurrecting conflicted state that resolved to deletion
  update-index: do not read HEAD and MERGE_HEAD unconditionally

1 files changed, 11 insertions, 4 deletions

diff --git a/builtin/checkout.c b/builtin/checkout.c
index f53612f468..f02434bc15 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -523,6 +523,15 @@ static int checkout_paths(const struct checkout_opts *opts,
 			    "--merge", "--conflict", "--staged");
 	}
 
+	/*
+	 * recreating unmerged index entries and writing out data from
+	 * unmerged index entries would make no sense when checking out
+	 * of a tree-ish.
+	 */
+	if ((opts->merge || opts->writeout_stage) && opts->source_tree)
+		die(_("'%s', '%s', or '%s' cannot be used when checking out of a tree"),
+		    "--merge", "--ours", "--theirs");
+
 	if (opts->patch_mode) {
 		enum add_p_mode patch_mode;
 		const char *rev = new_branch_info->name;
@@ -560,6 +569,8 @@ static int checkout_paths(const struct checkout_opts *opts,
 
 	if (opts->source_tree)
 		read_tree_some(opts->source_tree, &opts->pathspec);
+	if (opts->merge)
+		unmerge_index(&the_index, &opts->pathspec, CE_MATCHED);
 
 	ps_matched = xcalloc(opts->pathspec.nr, 1);
 
@@ -583,10 +594,6 @@ static int checkout_paths(const struct checkout_opts *opts,
 	}
 	free(ps_matched);
 
-	/* "checkout -m path" to recreate conflicted state */
-	if (opts->merge)
-		unmerge_marked_index(&the_index);
-
 	/* Any unmerged paths? */
 	for (pos = 0; pos < the_index.cache_nr; pos++) {
 		const struct cache_entry *ce = the_index.cache[pos];