sequencer: move check_todo_list_from_file() to rebase-interactive.c

The message contained in `edit_todo_list_advice' (sequencer.c) is
printed after the initial edit of the todo list if it can't be parsed or
if commits were dropped.  This is done either in complete_action() for
`rebase -i', or in check_todo_list_from_file() for `rebase -p'.

Since we want to add this check when editing the list, we also want to
use this message from edit_todo_list() (rebase-interactive.c).  To this
end, check_todo_list_from_file() is moved to rebase-interactive.c, and
`edit_todo_list_advice' is copied there.  In the next commit,
complete_action() will stop using it, and `edit_todo_list_advice' will
be removed from sequencer.c.

Signed-off-by: Alban Gruin <alban.gruin@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

rebase-interactive.c

@@ -6,6 +6,12 @@
 #include "commit-slab.h"
 #include "config.h"
 
+static const char edit_todo_list_advice[] =
+N_("You can fix this with 'git rebase --edit-todo' "
+"and then run 'git rebase --continue'.\n"
+"Or you can abort the rebase with 'git rebase"
+" --abort'.\n");
+
 enum missing_commit_check_level {
 	MISSING_COMMIT_CHECK_IGNORE = 0,
 	MISSING_COMMIT_CHECK_WARN,
@@ -189,3 +195,32 @@ int todo_list_check(struct todo_list *old_todo, struct todo_list *new_todo)
 	clear_commit_seen(&commit_seen);
 	return res;
 }
+
+int check_todo_list_from_file(struct repository *r)
+{
+	struct todo_list old_todo = TODO_LIST_INIT, new_todo = TODO_LIST_INIT;
+	int res = 0;
+
+	if (strbuf_read_file(&new_todo.buf, rebase_path_todo(), 0) < 0) {
+		res = error(_("could not read '%s'."), rebase_path_todo());
+		goto out;
+	}
+
+	if (strbuf_read_file(&old_todo.buf, rebase_path_todo_backup(), 0) < 0) {
+		res = error(_("could not read '%s'."), rebase_path_todo_backup());
+		goto out;
+	}
+
+	res = todo_list_parse_insn_buffer(r, old_todo.buf.buf, &old_todo);
+	if (!res)
+		res = todo_list_parse_insn_buffer(r, new_todo.buf.buf, &new_todo);
+	if (!res)
+		res = todo_list_check(&old_todo, &new_todo);
+	if (res)
+		fprintf(stderr, _(edit_todo_list_advice));
+out:
+	todo_list_release(&old_todo);
+	todo_list_release(&new_todo);
+
+	return res;
+}

rebase-interactive.h

@@ -13,4 +13,6 @@ int edit_todo_list(struct repository *r, struct todo_list *todo_list,
 		   const char *shortonto, unsigned flags);
 int todo_list_check(struct todo_list *old_todo, struct todo_list *new_todo);
 
+int check_todo_list_from_file(struct repository *r);
+
 #endif

sequencer.c

@@ -4991,35 +4991,6 @@ N_("You can fix this with 'git rebase --edit-todo' "
 "Or you can abort the rebase with 'git rebase"
 " --abort'.\n");
 
-int check_todo_list_from_file(struct repository *r)
-{
-	struct todo_list old_todo = TODO_LIST_INIT, new_todo = TODO_LIST_INIT;
-	int res = 0;
-
-	if (strbuf_read_file_or_whine(&new_todo.buf, rebase_path_todo()) < 0) {
-		res = -1;
-		goto out;
-	}
-
-	if (strbuf_read_file_or_whine(&old_todo.buf, rebase_path_todo_backup()) < 0) {
-		res = -1;
-		goto out;
-	}
-
-	res = todo_list_parse_insn_buffer(r, old_todo.buf.buf, &old_todo);
-	if (!res)
-		res = todo_list_parse_insn_buffer(r, new_todo.buf.buf, &new_todo);
-	if (!res)
-		res = todo_list_check(&old_todo, &new_todo);
-	if (res)
-		fprintf(stderr, _(edit_todo_list_advice));
-out:
-	todo_list_release(&old_todo);
-	todo_list_release(&new_todo);
-
-	return res;
-}
-
 /* skip picking commits whose parents are unchanged */
 static int skip_unnecessary_picks(struct repository *r,
 				  struct todo_list *todo_list,

sequencer.h

@@ -155,7 +155,6 @@ int sequencer_make_script(struct repository *r, struct strbuf *out, int argc,
 
 void todo_list_add_exec_commands(struct todo_list *todo_list,
 				 struct string_list *commands);
-int check_todo_list_from_file(struct repository *r);
 int complete_action(struct repository *r, struct replay_opts *opts, unsigned flags,
 		    const char *shortrevisions, const char *onto_name,
 		    struct commit *onto, const char *orig_head, struct string_list *commands,