[PATCH] sequencer: factor out strbuf_read_file_or_whine()

[René Scharfe <l.s.r@xxxxxx>]

Reduce code duplication by factoring out a function that reads an entire
file into a strbuf, or reports errors on stderr if something goes wrong.

Signed-off-by: Rene Scharfe <l.s.r@xxxxxx>
---
The difference to using strbuf_read_file() is more detailed error
messages for open(2) failures.  But I don't know if we need them -- or
under which circumstances reading todo files could fail anyway.  When
doing multiple rebases in parallel perhaps?

 sequencer.c | 74 +++++++++++++++++++++++--------------------------------------
 1 file changed, 28 insertions(+), 46 deletions(-)

diff --git a/sequencer.c b/sequencer.c
index e9baaf59bd..e34334f0ef 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -1869,22 +1869,31 @@ static int count_commands(struct todo_list *todo_list)
 	return count;
 }
 
+static ssize_t strbuf_read_file_or_whine(struct strbuf *sb, const char *path)
+{
+	int fd;
+	ssize_t len;
+
+	fd = open(path, O_RDONLY);
+	if (fd < 0)
+		return error_errno(_("could not open '%s'"), path);
+	len = strbuf_read(sb, fd, 0);
+	close(fd);
+	if (len < 0)
+		return error(_("could not read '%s'."), path);
+	return len;
+}
+
 static int read_populate_todo(struct todo_list *todo_list,
 			struct replay_opts *opts)
 {
 	struct stat st;
 	const char *todo_file = get_todo_path(opts);
-	int fd, res;
+	int res;
 
 	strbuf_reset(&todo_list->buf);
-	fd = open(todo_file, O_RDONLY);
-	if (fd < 0)
-		return error_errno(_("could not open '%s'"), todo_file);
-	if (strbuf_read(&todo_list->buf, fd, 0) < 0) {
-		close(fd);
-		return error(_("could not read '%s'."), todo_file);
-	}
-	close(fd);
+	if (strbuf_read_file_or_whine(&todo_list->buf, todo_file) < 0)
+		return -1;
 
 	res = stat(todo_file, &st);
 	if (res)
@@ -3151,20 +3160,13 @@ int check_todo_list(void)
 	struct strbuf todo_file = STRBUF_INIT;
 	struct todo_list todo_list = TODO_LIST_INIT;
 	struct strbuf missing = STRBUF_INIT;
-	int advise_to_edit_todo = 0, res = 0, fd, i;
+	int advise_to_edit_todo = 0, res = 0, i;
 
 	strbuf_addstr(&todo_file, rebase_path_todo());
-	fd = open(todo_file.buf, O_RDONLY);
-	if (fd < 0) {
-		res = error_errno(_("could not open '%s'"), todo_file.buf);
-		goto leave_check;
-	}
-	if (strbuf_read(&todo_list.buf, fd, 0) < 0) {
-		close(fd);
-		res = error(_("could not read '%s'."), todo_file.buf);
+	if (strbuf_read_file_or_whine(&todo_list.buf, todo_file.buf) < 0) {
+		res = -1;
 		goto leave_check;
 	}
-	close(fd);
 	advise_to_edit_todo = res =
 		parse_insn_buffer(todo_list.buf.buf, &todo_list);
 
@@ -3180,17 +3182,10 @@ int check_todo_list(void)
 
 	todo_list_release(&todo_list);
 	strbuf_addstr(&todo_file, ".backup");
-	fd = open(todo_file.buf, O_RDONLY);
-	if (fd < 0) {
-		res = error_errno(_("could not open '%s'"), todo_file.buf);
-		goto leave_check;
-	}
-	if (strbuf_read(&todo_list.buf, fd, 0) < 0) {
-		close(fd);
-		res = error(_("could not read '%s'."), todo_file.buf);
+	if (strbuf_read_file_or_whine(&todo_list.buf, todo_file.buf) < 0) {
+		res = -1;
 		goto leave_check;
 	}
-	close(fd);
 	strbuf_release(&todo_file);
 	res = !!parse_insn_buffer(todo_list.buf.buf, &todo_list);
 
@@ -3271,15 +3266,8 @@ int skip_unnecessary_picks(void)
 	}
 	strbuf_release(&buf);
 
-	fd = open(todo_file, O_RDONLY);
-	if (fd < 0) {
-		return error_errno(_("could not open '%s'"), todo_file);
-	}
-	if (strbuf_read(&todo_list.buf, fd, 0) < 0) {
-		close(fd);
-		return error(_("could not read '%s'."), todo_file);
-	}
-	close(fd);
+	if (strbuf_read_file_or_whine(&todo_list.buf, todo_file) < 0)
+		return -1;
 	if (parse_insn_buffer(todo_list.buf.buf, &todo_list) < 0) {
 		todo_list_release(&todo_list);
 		return -1;
@@ -3370,17 +3358,11 @@ int rearrange_squash(void)
 	const char *todo_file = rebase_path_todo();
 	struct todo_list todo_list = TODO_LIST_INIT;
 	struct hashmap subject2item;
-	int res = 0, rearranged = 0, *next, *tail, fd, i;
+	int res = 0, rearranged = 0, *next, *tail, i;
 	char **subjects;
 
-	fd = open(todo_file, O_RDONLY);
-	if (fd < 0)
-		return error_errno(_("could not open '%s'"), todo_file);
-	if (strbuf_read(&todo_list.buf, fd, 0) < 0) {
-		close(fd);
-		return error(_("could not read '%s'."), todo_file);
-	}
-	close(fd);
+	if (strbuf_read_file_or_whine(&todo_list.buf, todo_file) < 0)
+		return -1;
 	if (parse_insn_buffer(todo_list.buf.buf, &todo_list) < 0) {
 		todo_list_release(&todo_list);
 		return -1;
-- 
2.16.2