[PATCH v2 04/17] sequencer: configurably warn on non-existent files

[Denton Liu <liu.denton@gmail.com>]

In the future, we plan on externing read_oneliner(). Future users of
read_oneliner() will want the ability to output warnings in the event
that the `path` doesn't exist. Introduce the `warn_nonexistence`
parameter which, if true, would issue a warning when a file doesn't
exist by skipping the `!file_exists()` check and letting
`strbuf_read_file()` handle that case.

Mechanically replace uses of read_oneliner() in sequencer.c with the
following spatch so that current behaviour is maintained:

	@@
	expression a, b, c;
	@@
	  read_oneliner(a, b, c
	+ , 0
	  )

Signed-off-by: Denton Liu <liu.denton@gmail.com>
---
 sequencer.c | 32 ++++++++++++++++----------------
 1 file changed, 16 insertions(+), 16 deletions(-)

diff --git a/sequencer.c b/sequencer.c
index 5ba8b4383f..103cea1460 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -426,13 +426,13 @@ static int write_message(const void *buf, size_t len, const char *filename,
  *
  * Returns 1 if the file was read, 0 if it could not be read or does not exist.
  */
-static int read_oneliner(struct strbuf *buf,
-	const char *path, int skip_if_empty)
+static int read_oneliner(struct strbuf *buf, const char *path,
+			 int skip_if_empty, int warn_nonexistence)
 {
 	int ret = 0;
 	struct strbuf file_buf = STRBUF_INIT;
 
-	if (!file_exists(path))
+	if (!warn_nonexistence && !file_exists(path))
 		return 0;
 
 	if (strbuf_read_file(&file_buf, path, 0) < 0) {
@@ -2558,10 +2558,10 @@ void parse_strategy_opts(struct replay_opts *opts, char *raw_opts)
 static void read_strategy_opts(struct replay_opts *opts, struct strbuf *buf)
 {
 	strbuf_reset(buf);
-	if (!read_oneliner(buf, rebase_path_strategy(), 0))
+	if (!read_oneliner(buf, rebase_path_strategy(), 0, 0))
 		return;
 	opts->strategy = strbuf_detach(buf, NULL);
-	if (!read_oneliner(buf, rebase_path_strategy_opts(), 0))
+	if (!read_oneliner(buf, rebase_path_strategy_opts(), 0, 0))
 		return;
 
 	parse_strategy_opts(opts, buf->buf);
@@ -2572,7 +2572,7 @@ static int read_populate_opts(struct replay_opts *opts)
 	if (is_rebase_i(opts)) {
 		struct strbuf buf = STRBUF_INIT;
 
-		if (read_oneliner(&buf, rebase_path_gpg_sign_opt(), 1)) {
+		if (read_oneliner(&buf, rebase_path_gpg_sign_opt(), 1, 0)) {
 			if (!starts_with(buf.buf, "-S"))
 				strbuf_reset(&buf);
 			else {
@@ -2582,7 +2582,7 @@ static int read_populate_opts(struct replay_opts *opts)
 			strbuf_reset(&buf);
 		}
 
-		if (read_oneliner(&buf, rebase_path_allow_rerere_autoupdate(), 1)) {
+		if (read_oneliner(&buf, rebase_path_allow_rerere_autoupdate(), 1, 0)) {
 			if (!strcmp(buf.buf, "--rerere-autoupdate"))
 				opts->allow_rerere_auto = RERERE_AUTOUPDATE;
 			else if (!strcmp(buf.buf, "--no-rerere-autoupdate"))
@@ -2618,7 +2618,7 @@ static int read_populate_opts(struct replay_opts *opts)
 		strbuf_release(&buf);
 
 		if (read_oneliner(&opts->current_fixups,
-				  rebase_path_current_fixups(), 1)) {
+				  rebase_path_current_fixups(), 1, 0)) {
 			const char *p = opts->current_fixups.buf;
 			opts->current_fixup_count = 1;
 			while ((p = strchr(p, '\n'))) {
@@ -2627,7 +2627,7 @@ static int read_populate_opts(struct replay_opts *opts)
 			}
 		}
 
-		if (read_oneliner(&buf, rebase_path_squash_onto(), 0)) {
+		if (read_oneliner(&buf, rebase_path_squash_onto(), 0, 0)) {
 			if (get_oid_hex(buf.buf, &opts->squash_onto) < 0)
 				return error(_("unusable squash-onto"));
 			opts->have_squash_onto = 1;
@@ -3759,7 +3759,7 @@ static int apply_autostash(struct replay_opts *opts)
 	struct child_process child = CHILD_PROCESS_INIT;
 	int ret = 0;
 
-	if (!read_oneliner(&stash_sha1, rebase_path_autostash(), 1)) {
+	if (!read_oneliner(&stash_sha1, rebase_path_autostash(), 1, 0)) {
 		strbuf_release(&stash_sha1);
 		return 0;
 	}
@@ -4093,7 +4093,7 @@ static int pick_commits(struct repository *r,
 		if (todo_list->current < todo_list->nr)
 			return 0;
 
-		if (read_oneliner(&head_ref, rebase_path_head_name(), 0) &&
+		if (read_oneliner(&head_ref, rebase_path_head_name(), 0, 0) &&
 				starts_with(head_ref.buf, "refs/")) {
 			const char *msg;
 			struct object_id head, orig;
@@ -4106,13 +4106,13 @@ static int pick_commits(struct repository *r,
 				strbuf_release(&buf);
 				return res;
 			}
-			if (!read_oneliner(&buf, rebase_path_orig_head(), 0) ||
+			if (!read_oneliner(&buf, rebase_path_orig_head(), 0, 0) ||
 					get_oid_hex(buf.buf, &orig)) {
 				res = error(_("could not read orig-head"));
 				goto cleanup_head_ref;
 			}
 			strbuf_reset(&buf);
-			if (!read_oneliner(&buf, rebase_path_onto(), 0)) {
+			if (!read_oneliner(&buf, rebase_path_onto(), 0, 0)) {
 				res = error(_("could not read 'onto'"));
 				goto cleanup_head_ref;
 			}
@@ -4145,7 +4145,7 @@ static int pick_commits(struct repository *r,
 				DIFF_FORMAT_DIFFSTAT;
 			log_tree_opt.disable_stdin = 1;
 
-			if (read_oneliner(&buf, rebase_path_orig_head(), 0) &&
+			if (read_oneliner(&buf, rebase_path_orig_head(), 0, 0) &&
 			    !get_oid(buf.buf, &orig) &&
 			    !get_oid("HEAD", &head)) {
 				diff_tree_oid(&orig, &head, "",
@@ -4230,7 +4230,7 @@ static int commit_staged_changes(struct repository *r,
 
 		if (get_oid("HEAD", &head))
 			return error(_("cannot amend non-existing commit"));
-		if (!read_oneliner(&rev, rebase_path_amend(), 0))
+		if (!read_oneliner(&rev, rebase_path_amend(), 0, 0))
 			return error(_("invalid file: '%s'"), rebase_path_amend());
 		if (get_oid_hex(rev.buf, &to_amend))
 			return error(_("invalid contents: '%s'"),
@@ -4391,7 +4391,7 @@ int sequencer_continue(struct repository *r, struct replay_opts *opts)
 		struct strbuf buf = STRBUF_INIT;
 		struct object_id oid;
 
-		if (read_oneliner(&buf, rebase_path_stopped_sha(), 1) &&
+		if (read_oneliner(&buf, rebase_path_stopped_sha(), 1, 0) &&
 		    !get_oid_committish(buf.buf, &oid))
 			record_in_rewritten(&oid, peek_command(&todo_list, 0));
 		strbuf_release(&buf);
-- 
2.24.1.810.g65a2f617f4