From: Phillip Wood Date: Mon, 10 Nov 2025 16:38:55 GMT Subject: Re: [PATCH v6 3/4] trailer: append trailers in-process and drop the fork to `interpret-trailers` Message-ID: In-Reply-To: <20251105142944.73061-4-me@linux.beauty> Hi Li On 05/11/2025 14:29, Li Chen wrote: > From: Li Chen > > diff --git a/builtin/commit.c b/builtin/commit.c > index 0243f17d53..67070d6a54 100644 > --- a/builtin/commit.c > +++ b/builtin/commit.c > @@ -1719,7 +1719,7 @@ int cmd_commit(int argc, > OPT_STRING(0, "fixup", &fixup_message, N_("[(amend|reword):]commit"), N_("use autosquash formatted message to fixup or amend/reword specified commit")), > OPT_STRING(0, "squash", &squash_message, N_("commit"), N_("use autosquash formatted message to squash specified commit")), > OPT_BOOL(0, "reset-author", &renew_authorship, N_("the commit is authored by me now (used with -C/-c/--amend)")), > - OPT_PASSTHRU_ARGV(0, "trailer", &trailer_args, N_("trailer"), N_("add custom trailer(s)"), PARSE_OPT_NONEG), We have OPT_STRVEC to handle this. The commit message should explain why we're doing this (because we only want to pass the value to amend_file_with_trailers()). Alternatively we could use skip_prefix() in amend_file_with_trailers() to skip the "--trailer=" prefix in this patch and then clean it in a separate patch. > + OPT_CALLBACK_F(0, "trailer", &trailer_args, N_("trailer"), N_("add custom trailer(s)"), PARSE_OPT_NONEG, parse_opt_strvec), > OPT_BOOL('s', "signoff", &signoff, N_("add a Signed-off-by trailer")), > OPT_FILENAME('t', "template", &template_file, N_("use specified template file")), > OPT_BOOL('e', "edit", &edit_flag, N_("force edit of commit")), > diff --git a/builtin/interpret-trailers.c b/builtin/interpret-trailers.c > index bce2e791d6..268a43372b 100644 > --- a/builtin/interpret-trailers.c > +++ b/builtin/interpret-trailers.c > > @@ -142,21 +110,15 @@ static void interpret_trailers(const struct process_trailer_options *opts, > { > struct strbuf sb = STRBUF_INIT; > struct strbuf out = STRBUF_INIT; > - FILE *outfile = stdout; > - > - trailer_config_init(); Why is this being moved? > read_input_file(&sb, file); > > - if (opts->in_place) > - outfile = create_in_place_tempfile(file); > - > process_trailers(opts, new_trailer_head, &sb, &out); > > - fwrite(out.buf, out.len, 1, outfile); > if (opts->in_place) > - if (rename_tempfile(&trailers_tempfile, file)) > - die_errno(_("could not rename temporary file to %s"), file); > + write_file_buf(file, out.buf, out.len); This truncates the existing file which means that if there is a error while writing the new version the user is now left with garbage rather than the original file which does not seem like a good idea. > diff --git a/trailer.c b/trailer.c> index b735ec8a53..f5838f5699 100644 > --- a/trailer.c > +++ b/trailer.c > > @@ -1224,18 +1226,66 @@ void trailer_iterator_release(struct trailer_iterator *iter) > strbuf_release(&iter->key); > } > > -int amend_file_with_trailers(const char *path, const struct strvec *trailer_args) > +static int amend_strbuf_with_trailers(struct strbuf *buf, > + const struct strvec *trailer_args) > { > - struct child_process run_trailer = CHILD_PROCESS_INIT; > - > - run_trailer.git_cmd = 1; > - strvec_pushl(&run_trailer.args, "interpret-trailers", > - "--in-place", "--no-divider", > - path, NULL); > - strvec_pushv(&run_trailer.args, trailer_args->v); > - return run_command(&run_trailer); > + struct process_trailer_options opts = PROCESS_TRAILER_OPTIONS_INIT; > + LIST_HEAD(new_trailer_head); > + struct strbuf out = STRBUF_INIT; > + size_t i; > + > + opts.no_divider = 1; > + > + for (i = 0; i < trailer_args->nr; i++) { > + const char *text = trailer_args->v[i]; > + struct new_trailer_item *item; > + > + if (!*text) > + continue; Isn't it an error to pass an empty argument to "--trailer"? > + item = xcalloc(1, sizeof(*item)); > + INIT_LIST_HEAD(&item->list); I don't think we need this as "item->prev" and "item->next" are set by list_add_tail() below. We initialize "where", "if_exists" and "if_missing" to zero which matches what builtin/interpret-trailers.c does if the user does not specify any of those options - good. > + item->text = text; > + list_add_tail(&item->list, &new_trailer_head); > + } > + > + process_trailers(&opts, &new_trailer_head, buf, &out); > + > + strbuf_swap(buf, &out); > + strbuf_release(&out); > + while (!list_empty(&new_trailer_head)) { > + struct new_trailer_item *item = > + list_first_entry(&new_trailer_head, struct new_trailer_item, list); > + list_del(&item->list); > + free(item); We have free_trailers() to do this for us. > + } > + return 0; > } > > +int amend_file_with_trailers(const char *path, > + const struct strvec *trailer_args) > +{ > + struct strbuf buf = STRBUF_INIT; > + > + if (!trailer_args || !trailer_args->nr) > + return 0; Isn't it a bug to pass a NULL trailer_args? > + if (strbuf_read_file(&buf, path, 0) < 0) > + return error_errno("could not read '%s'", path); > + > + if (amend_strbuf_with_trailers(&buf, trailer_args)) { > + strbuf_release(&buf); > + return error("failed to append trailers"); > + } > + > + if (write_file_buf_gently(path, buf.buf, buf.len)) { > + strbuf_release(&buf); > + return -1; > + } > + > + strbuf_release(&buf); > + return 0; > + } This looks like a faithful conversion of the original with the caveat that it expects to be passed an array of trailer arguments without the "--trailer=" prefix. Good I'll take a look at patch 4 tomorrow but so far these version is looking much nicer than the last round. Thanks Phillip > void process_trailers(const struct process_trailer_options *opts, > struct list_head *new_trailer_head, > struct strbuf *sb, struct strbuf *out) > diff --git a/trailer.h b/trailer.h > index 44d406b763..daea46ca5d 100644 > --- a/trailer.h > +++ b/trailer.h > @@ -196,9 +196,8 @@ int trailer_iterator_advance(struct trailer_iterator *iter); > void trailer_iterator_release(struct trailer_iterator *iter); > > /* > - * Augment a file to add trailers to it by running git-interpret-trailers. > - * This calls run_command() and its return value is the same (i.e. 0 for > - * success, various non-zero for other errors). See run-command.h. > + * Augment a file to add trailers to it (similar to 'git interpret-trailers'). > + * Returns 0 on success or a non-zero error code on failure. > */ > int amend_file_with_trailers(const char *path, const struct strvec *trailer_args); > > diff --git a/wrapper.c b/wrapper.c > index 3d507d4204..1f12dbb2fa 100644 > --- a/wrapper.c > +++ b/wrapper.c > @@ -688,6 +688,22 @@ void write_file_buf(const char *path, const char *buf, size_t len) > die_errno(_("could not close '%s'"), path); > } > > +int write_file_buf_gently(const char *path, const char *buf, size_t len) > +{ > + int fd = open(path, O_WRONLY | O_CREAT | O_TRUNC, 0666); > + > + if (fd < 0) > + return error_errno(_("could not open '%s'"), path); > + if (write_in_full(fd, buf, len) < 0) { > + int ret = error_errno(_("could not write to '%s'"), path); > + close(fd); > + return ret; > + } > + if (close(fd)) > + return error_errno(_("could not close '%s'"), path); > + return 0; > +} > + > void write_file(const char *path, const char *fmt, ...) > { > va_list params; > diff --git a/wrapper.h b/wrapper.h > index 44a8597ac3..e5f867b200 100644 > --- a/wrapper.h > +++ b/wrapper.h > @@ -56,6 +56,12 @@ static inline ssize_t write_str_in_full(int fd, const char *str) > */ > void write_file_buf(const char *path, const char *buf, size_t len); > > +/** > + * Like write_file_buf(), but report errors instead of exiting. Returns 0 on > + * success or a negative value on error after emitting a message. > + */ > +int write_file_buf_gently(const char *path, const char *buf, size_t len); > + > /** > * Like write_file_buf(), but format the contents into a buffer first. > * Additionally, write_file() will append a newline if one is not already