checkout: add --progress option

Under normal circumstances, and like other git commands,
git checkout will write progress info to stderr if
attached to a terminal. This option allows progress
to be forced even if not using a terminal. Also,
progress can be skipped if using option --no-progress.

Signed-off-by: Edmundo Carmona Antoranz <eantoranz@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-checkout.txt

@@ -107,6 +107,12 @@ OPTIONS
 --quiet::
 	Quiet, suppress feedback messages.
 
+--[no-]progress::
+	Progress status is reported on the standard error stream
+	by default when it is attached to a terminal, unless `--quiet`
+	is specified. This flag enables progress reporting even if not
+	attached to a terminal, regardless of `--quiet`.
+
 -f::
 --force::
 	When switching branches, proceed even if the index or the

builtin/checkout.c

@@ -37,6 +37,7 @@ struct checkout_opts {
 	int overwrite_ignore;
 	int ignore_skipworktree;
 	int ignore_other_worktrees;
+	int show_progress;
 
 	const char *new_branch;
 	const char *new_branch_force;
@@ -417,7 +418,7 @@ static int reset_tree(struct tree *tree, const struct checkout_opts *o,
 	opts.reset = 1;
 	opts.merge = 1;
 	opts.fn = oneway_merge;
-	opts.verbose_update = !o->quiet && isatty(2);
+	opts.verbose_update = o->show_progress;
 	opts.src_index = &the_index;
 	opts.dst_index = &the_index;
 	parse_tree(tree);
@@ -501,7 +502,7 @@ static int merge_working_tree(const struct checkout_opts *opts,
 		topts.update = 1;
 		topts.merge = 1;
 		topts.gently = opts->merge && old->commit;
-		topts.verbose_update = !opts->quiet && isatty(2);
+		topts.verbose_update = opts->show_progress;
 		topts.fn = twoway_merge;
 		if (opts->overwrite_ignore) {
 			topts.dir = xcalloc(1, sizeof(*topts.dir));
@@ -1156,13 +1157,15 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 				N_("second guess 'git checkout <no-such-branch>'")),
 		OPT_BOOL(0, "ignore-other-worktrees", &opts.ignore_other_worktrees,
 			 N_("do not check if another worktree is holding the given ref")),
+		OPT_BOOL(0, "progress", &opts.show_progress, N_("force progress reporting")),
 		OPT_END(),
 	};
 
 	memset(&opts, 0, sizeof(opts));
 	memset(&new, 0, sizeof(new));
 	opts.overwrite_ignore = 1;
 	opts.prefix = prefix;
+	opts.show_progress = -1;
 
 	gitmodules_config();
 	git_config(git_checkout_config, &opts);
@@ -1172,6 +1175,13 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 	argc = parse_options(argc, argv, prefix, options, checkout_usage,
 			     PARSE_OPT_KEEP_DASHDASH);
 
+	if (opts.show_progress < 0) {
+		if (opts.quiet)
+			opts.show_progress = 0;
+		else
+			opts.show_progress = isatty(2);
+	}
+
 	if (conflict_style) {
 		opts.merge = 1; /* implied */
 		git_xmerge_config("merge.conflictstyle", conflict_style, NULL);