[PATCH] sequencer: factor out strbuf_read_file_or_whine()

[René Scharfe]

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....@web.de>
---
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