builtin-am: extract patch and commit info with git-mailinfo

For the purpose of applying the patch and committing the results,
implement extracting the patch data, commit message and authorship from
an e-mail message using git-mailinfo.

git-mailinfo is run as a separate process, but ideally in the future,
we should be be able to access its functionality directly without
spawning a new process.

Helped-by: Junio C Hamano <gitster@pobox.com>
Helped-by: Jeff King <peff@peff.net>
Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Paul Tan <pyokagan@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Paul Tan 2015-08-04 21:51:28 +08:00 committed by Junio C Hamano
parent c29807b27d
commit 3e20dcf367

View File

@ -9,6 +9,23 @@
#include "parse-options.h"
#include "dir.h"
#include "run-command.h"
#include "quote.h"
/**
* Returns 1 if the file is empty or does not exist, 0 otherwise.
*/
static int is_empty_file(const char *filename)
{
struct stat st;
if (stat(filename, &st) < 0) {
if (errno == ENOENT)
return 1;
die_errno(_("could not stat %s"), filename);
}
return !st.st_size;
}
/**
* Like strbuf_getline(), but treats both '\n' and "\r\n" as line terminators.
@ -38,6 +55,13 @@ struct am_state {
int cur;
int last;
/* commit metadata and message */
char *author_name;
char *author_email;
char *author_date;
char *msg;
size_t msg_len;
/* number of digits in patch filename */
int prec;
};
@ -62,6 +86,10 @@ static void am_state_init(struct am_state *state, const char *dir)
static void am_state_release(struct am_state *state)
{
free(state->dir);
free(state->author_name);
free(state->author_email);
free(state->author_date);
free(state->msg);
}
/**
@ -111,6 +139,161 @@ static int read_state_file(struct strbuf *sb, const struct am_state *state,
die_errno(_("could not read '%s'"), am_path(state, file));
}
/**
* Reads a KEY=VALUE shell variable assignment from `fp`, returning the VALUE
* as a newly-allocated string. VALUE must be a quoted string, and the KEY must
* match `key`. Returns NULL on failure.
*
* This is used by read_author_script() to read the GIT_AUTHOR_* variables from
* the author-script.
*/
static char *read_shell_var(FILE *fp, const char *key)
{
struct strbuf sb = STRBUF_INIT;
const char *str;
if (strbuf_getline(&sb, fp, '\n'))
goto fail;
if (!skip_prefix(sb.buf, key, &str))
goto fail;
if (!skip_prefix(str, "=", &str))
goto fail;
strbuf_remove(&sb, 0, str - sb.buf);
str = sq_dequote(sb.buf);
if (!str)
goto fail;
return strbuf_detach(&sb, NULL);
fail:
strbuf_release(&sb);
return NULL;
}
/**
* Reads and parses the state directory's "author-script" file, and sets
* state->author_name, state->author_email and state->author_date accordingly.
* Returns 0 on success, -1 if the file could not be parsed.
*
* The author script is of the format:
*
* GIT_AUTHOR_NAME='$author_name'
* GIT_AUTHOR_EMAIL='$author_email'
* GIT_AUTHOR_DATE='$author_date'
*
* where $author_name, $author_email and $author_date are quoted. We are strict
* with our parsing, as the file was meant to be eval'd in the old git-am.sh
* script, and thus if the file differs from what this function expects, it is
* better to bail out than to do something that the user does not expect.
*/
static int read_author_script(struct am_state *state)
{
const char *filename = am_path(state, "author-script");
FILE *fp;
assert(!state->author_name);
assert(!state->author_email);
assert(!state->author_date);
fp = fopen(filename, "r");
if (!fp) {
if (errno == ENOENT)
return 0;
die_errno(_("could not open '%s' for reading"), filename);
}
state->author_name = read_shell_var(fp, "GIT_AUTHOR_NAME");
if (!state->author_name) {
fclose(fp);
return -1;
}
state->author_email = read_shell_var(fp, "GIT_AUTHOR_EMAIL");
if (!state->author_email) {
fclose(fp);
return -1;
}
state->author_date = read_shell_var(fp, "GIT_AUTHOR_DATE");
if (!state->author_date) {
fclose(fp);
return -1;
}
if (fgetc(fp) != EOF) {
fclose(fp);
return -1;
}
fclose(fp);
return 0;
}
/**
* Saves state->author_name, state->author_email and state->author_date in the
* state directory's "author-script" file.
*/
static void write_author_script(const struct am_state *state)
{
struct strbuf sb = STRBUF_INIT;
strbuf_addstr(&sb, "GIT_AUTHOR_NAME=");
sq_quote_buf(&sb, state->author_name);
strbuf_addch(&sb, '\n');
strbuf_addstr(&sb, "GIT_AUTHOR_EMAIL=");
sq_quote_buf(&sb, state->author_email);
strbuf_addch(&sb, '\n');
strbuf_addstr(&sb, "GIT_AUTHOR_DATE=");
sq_quote_buf(&sb, state->author_date);
strbuf_addch(&sb, '\n');
write_file(am_path(state, "author-script"), 1, "%s", sb.buf);
strbuf_release(&sb);
}
/**
* Reads the commit message from the state directory's "final-commit" file,
* setting state->msg to its contents and state->msg_len to the length of its
* contents in bytes.
*
* Returns 0 on success, -1 if the file does not exist.
*/
static int read_commit_msg(struct am_state *state)
{
struct strbuf sb = STRBUF_INIT;
assert(!state->msg);
if (read_state_file(&sb, state, "final-commit", 0) < 0) {
strbuf_release(&sb);
return -1;
}
state->msg = strbuf_detach(&sb, &state->msg_len);
return 0;
}
/**
* Saves state->msg in the state directory's "final-commit" file.
*/
static void write_commit_msg(const struct am_state *state)
{
int fd;
const char *filename = am_path(state, "final-commit");
fd = xopen(filename, O_WRONLY | O_CREAT, 0666);
if (write_in_full(fd, state->msg, state->msg_len) < 0)
die_errno(_("could not write to %s"), filename);
close(fd);
}
/**
* Loads state from disk.
*/
@ -126,6 +309,11 @@ static void am_load(struct am_state *state)
die("BUG: state file 'last' does not exist");
state->last = strtol(sb.buf, NULL, 10);
if (read_author_script(state) < 0)
die(_("could not parse author script"));
read_commit_msg(state);
strbuf_release(&sb);
}
@ -318,19 +506,148 @@ static void am_setup(struct am_state *state, enum patch_format patch_format,
*/
static void am_next(struct am_state *state)
{
free(state->author_name);
state->author_name = NULL;
free(state->author_email);
state->author_email = NULL;
free(state->author_date);
state->author_date = NULL;
free(state->msg);
state->msg = NULL;
state->msg_len = 0;
unlink(am_path(state, "author-script"));
unlink(am_path(state, "final-commit"));
state->cur++;
write_file(am_path(state, "next"), 1, "%d", state->cur);
}
/**
* Returns the filename of the current patch email.
*/
static const char *msgnum(const struct am_state *state)
{
static struct strbuf sb = STRBUF_INIT;
strbuf_reset(&sb);
strbuf_addf(&sb, "%0*d", state->prec, state->cur);
return sb.buf;
}
/**
* Parses `mail` using git-mailinfo, extracting its patch and authorship info.
* state->msg will be set to the patch message. state->author_name,
* state->author_email and state->author_date will be set to the patch author's
* name, email and date respectively. The patch body will be written to the
* state directory's "patch" file.
*
* Returns 1 if the patch should be skipped, 0 otherwise.
*/
static int parse_mail(struct am_state *state, const char *mail)
{
FILE *fp;
struct child_process cp = CHILD_PROCESS_INIT;
struct strbuf sb = STRBUF_INIT;
struct strbuf msg = STRBUF_INIT;
struct strbuf author_name = STRBUF_INIT;
struct strbuf author_date = STRBUF_INIT;
struct strbuf author_email = STRBUF_INIT;
int ret = 0;
cp.git_cmd = 1;
cp.in = xopen(mail, O_RDONLY, 0);
cp.out = xopen(am_path(state, "info"), O_WRONLY | O_CREAT, 0777);
argv_array_push(&cp.args, "mailinfo");
argv_array_push(&cp.args, am_path(state, "msg"));
argv_array_push(&cp.args, am_path(state, "patch"));
if (run_command(&cp) < 0)
die("could not parse patch");
close(cp.in);
close(cp.out);
/* Extract message and author information */
fp = xfopen(am_path(state, "info"), "r");
while (!strbuf_getline(&sb, fp, '\n')) {
const char *x;
if (skip_prefix(sb.buf, "Subject: ", &x)) {
if (msg.len)
strbuf_addch(&msg, '\n');
strbuf_addstr(&msg, x);
} else if (skip_prefix(sb.buf, "Author: ", &x))
strbuf_addstr(&author_name, x);
else if (skip_prefix(sb.buf, "Email: ", &x))
strbuf_addstr(&author_email, x);
else if (skip_prefix(sb.buf, "Date: ", &x))
strbuf_addstr(&author_date, x);
}
fclose(fp);
/* Skip pine's internal folder data */
if (!strcmp(author_name.buf, "Mail System Internal Data")) {
ret = 1;
goto finish;
}
if (is_empty_file(am_path(state, "patch"))) {
printf_ln(_("Patch is empty. Was it split wrong?"));
exit(128);
}
strbuf_addstr(&msg, "\n\n");
if (strbuf_read_file(&msg, am_path(state, "msg"), 0) < 0)
die_errno(_("could not read '%s'"), am_path(state, "msg"));
stripspace(&msg, 0);
assert(!state->author_name);
state->author_name = strbuf_detach(&author_name, NULL);
assert(!state->author_email);
state->author_email = strbuf_detach(&author_email, NULL);
assert(!state->author_date);
state->author_date = strbuf_detach(&author_date, NULL);
assert(!state->msg);
state->msg = strbuf_detach(&msg, &state->msg_len);
finish:
strbuf_release(&msg);
strbuf_release(&author_date);
strbuf_release(&author_email);
strbuf_release(&author_name);
strbuf_release(&sb);
return ret;
}
/**
* Applies all queued mail.
*/
static void am_run(struct am_state *state)
{
while (state->cur <= state->last) {
const char *mail = am_path(state, msgnum(state));
if (!file_exists(mail))
goto next;
if (parse_mail(state, mail))
goto next; /* mail should be skipped */
write_author_script(state);
write_commit_msg(state);
/* NEEDSWORK: Patch application not implemented yet */
next:
am_next(state);
}