advice.h: add advise_on_moving_dirty_path()

Add an advice.

When the user use `git mv --sparse <dirty-path> <destination>`, Git
will warn the user to use `git add --sparse <paths>` then use
`git sparse-checkout reapply` to apply the sparsity rules.

Add a few lines to previous "move dirty path" tests so we can test
this new advice is working.

Suggested-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Shaoxuan Yuan <shaoxuan.yuan02@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 19 insertions, 0 deletions

diff --git a/advice.c b/advice.c
index 6fda9edbc2..fd18968943 100644
--- a/advice.c
+++ b/advice.c
@@ -261,3 +261,22 @@ void detach_advice(const char *new_name)
 
 	fprintf(stderr, fmt, new_name);
 }
+
+void advise_on_moving_dirty_path(struct string_list *pathspec_list)
+{
+	struct string_list_item *item;
+
+	if (!pathspec_list->nr)
+		return;
+
+	fprintf(stderr, _("The following paths have been moved outside the\n"
+			  "sparse-checkout definition but are not sparse due to local\n"
+			  "modifications.\n"));
+	for_each_string_list_item(item, pathspec_list)
+		fprintf(stderr, "%s\n", item->string);
+
+	advise_if_enabled(ADVICE_UPDATE_SPARSE_PATH,
+			  _("To correct the sparsity of these paths, do the following:\n"
+			    "* Use \"git add --sparse <paths>\" to update the index\n"
+			    "* Use \"git sparse-checkout reapply\" to apply the sparsity rules"));
+}