[PATCH v3 37/38] sequencer (rebase -i): write the progress into files

[Johannes Schindelin <johannes.schindelin@xxxxxx>]

For the benefit of e.g. the shell prompt, the interactive rebase not
only displays the progress for the user to see, but also writes it into
the msgnum/end files in the state directory.

Teach the sequencer this new trick.

Signed-off-by: Johannes Schindelin <johannes.schindelin@xxxxxx>
---
 sequencer.c | 30 +++++++++++++++++++++++++++---
 1 file changed, 27 insertions(+), 3 deletions(-)

diff --git a/sequencer.c b/sequencer.c
index 2c9c555ab6..b39cd21e03 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -47,6 +47,16 @@ static GIT_PATH_FUNC(rebase_path_todo, "rebase-merge/git-rebase-todo")
  */
 static GIT_PATH_FUNC(rebase_path_done, "rebase-merge/done")
 /*
+ * The file to keep track of how many commands were already processed (e.g.
+ * for the prompt).
+ */
+static GIT_PATH_FUNC(rebase_path_msgnum, "rebase-merge/msgnum");
+/*
+ * The file to keep track of how many commands are to be processed in total
+ * (e.g. for the prompt).
+ */
+static GIT_PATH_FUNC(rebase_path_msgtotal, "rebase-merge/end");
+/*
  * The commit message that is planned to be used for any changes that
  * need to be committed following a user interaction.
  */
@@ -1353,6 +1363,7 @@ static int read_populate_todo(struct todo_list *todo_list,
 
 	if (is_rebase_i(opts)) {
 		struct todo_list done = TODO_LIST_INIT;
+		FILE *f = fopen(rebase_path_msgtotal(), "w");
 
 		if (strbuf_read_file(&done.buf, rebase_path_done(), 0) > 0 &&
 				!parse_insn_buffer(done.buf.buf, &done))
@@ -1362,8 +1373,12 @@ static int read_populate_todo(struct todo_list *todo_list,
 
 		todo_list->total_nr = todo_list->done_nr
 			+ count_commands(todo_list);
-
 		todo_list_release(&done);
+
+		if (f) {
+			fprintf(f, "%d\n", todo_list->total_nr);
+			fclose(f);
+		}
 	}
 
 	return 0;
@@ -1947,11 +1962,20 @@ static int pick_commits(struct todo_list *todo_list, struct replay_opts *opts)
 		if (save_todo(todo_list, opts))
 			return -1;
 		if (is_rebase_i(opts)) {
-			if (item->command != TODO_COMMENT)
+			if (item->command != TODO_COMMENT) {
+				FILE *f = fopen(rebase_path_msgnum(), "w");
+
+				todo_list->done_nr++;
+
+				if (f) {
+					fprintf(f, "%d\n", todo_list->done_nr);
+					fclose(f);
+				}
 				fprintf(stderr, "Rebasing (%d/%d)%s",
-					++(todo_list->done_nr),
+					todo_list->done_nr,
 					todo_list->total_nr,
 					opts->verbose ? "\n" : "\r");
+			}
 			unlink(rebase_path_message());
 			unlink(rebase_path_author_script());
 			unlink(rebase_path_stopped_sha());
-- 
2.11.0.rc3.windows.1