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git/builtin/update-ref.c
Ronnie Sahlberg 8e34800e5b refs.c: change ref_transaction_update() to do error checking and return status
Update ref_transaction_update() do some basic error checking and return
non-zero on error. Update all callers to check ref_transaction_update() for
error. There are currently no conditions in _update that will return error but
there will be in the future. Add an err argument that will be updated on
failure. In future patches we will start doing both locking and checking
for name conflicts in _update instead of _commit at which time this function
will start returning errors for these conditions.

Also check for BUGs during update and die(BUG:...) if we are calling
_update with have_old but the old_sha1 pointer is NULL.

Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Acked-by: Michael Haggerty <mhagger@alum.mit.edu>
2014-07-14 11:54:42 -07:00

407 lines
11 KiB
C

#include "cache.h"
#include "refs.h"
#include "builtin.h"
#include "parse-options.h"
#include "quote.h"
#include "argv-array.h"
static const char * const git_update_ref_usage[] = {
N_("git update-ref [options] -d <refname> [<oldval>]"),
N_("git update-ref [options] <refname> <newval> [<oldval>]"),
N_("git update-ref [options] --stdin [-z]"),
NULL
};
static struct ref_transaction *transaction;
static char line_termination = '\n';
static int update_flags;
static struct strbuf err = STRBUF_INIT;
/*
* Parse one whitespace- or NUL-terminated, possibly C-quoted argument
* and append the result to arg. Return a pointer to the terminator.
* Die if there is an error in how the argument is C-quoted. This
* function is only used if not -z.
*/
static const char *parse_arg(const char *next, struct strbuf *arg)
{
if (*next == '"') {
const char *orig = next;
if (unquote_c_style(arg, next, &next))
die("badly quoted argument: %s", orig);
if (*next && !isspace(*next))
die("unexpected character after quoted argument: %s", orig);
} else {
while (*next && !isspace(*next))
strbuf_addch(arg, *next++);
}
return next;
}
/*
* Parse the reference name immediately after "command SP". If not
* -z, then handle C-quoting. Return a pointer to a newly allocated
* string containing the name of the reference, or NULL if there was
* an error. Update *next to point at the character that terminates
* the argument. Die if C-quoting is malformed or the reference name
* is invalid.
*/
static char *parse_refname(struct strbuf *input, const char **next)
{
struct strbuf ref = STRBUF_INIT;
if (line_termination) {
/* Without -z, use the next argument */
*next = parse_arg(*next, &ref);
} else {
/* With -z, use everything up to the next NUL */
strbuf_addstr(&ref, *next);
*next += ref.len;
}
if (!ref.len) {
strbuf_release(&ref);
return NULL;
}
if (check_refname_format(ref.buf, REFNAME_ALLOW_ONELEVEL))
die("invalid ref format: %s", ref.buf);
return strbuf_detach(&ref, NULL);
}
/*
* The value being parsed is <oldvalue> (as opposed to <newvalue>; the
* difference affects which error messages are generated):
*/
#define PARSE_SHA1_OLD 0x01
/*
* For backwards compatibility, accept an empty string for update's
* <newvalue> in binary mode to be equivalent to specifying zeros.
*/
#define PARSE_SHA1_ALLOW_EMPTY 0x02
/*
* Parse an argument separator followed by the next argument, if any.
* If there is an argument, convert it to a SHA-1, write it to sha1,
* set *next to point at the character terminating the argument, and
* return 0. If there is no argument at all (not even the empty
* string), return 1 and leave *next unchanged. If the value is
* provided but cannot be converted to a SHA-1, die. flags can
* include PARSE_SHA1_OLD and/or PARSE_SHA1_ALLOW_EMPTY.
*/
static int parse_next_sha1(struct strbuf *input, const char **next,
unsigned char *sha1,
const char *command, const char *refname,
int flags)
{
struct strbuf arg = STRBUF_INIT;
int ret = 0;
if (*next == input->buf + input->len)
goto eof;
if (line_termination) {
/* Without -z, consume SP and use next argument */
if (!**next || **next == line_termination)
return 1;
if (**next != ' ')
die("%s %s: expected SP but got: %s",
command, refname, *next);
(*next)++;
*next = parse_arg(*next, &arg);
if (arg.len) {
if (get_sha1(arg.buf, sha1))
goto invalid;
} else {
/* Without -z, an empty value means all zeros: */
hashclr(sha1);
}
} else {
/* With -z, read the next NUL-terminated line */
if (**next)
die("%s %s: expected NUL but got: %s",
command, refname, *next);
(*next)++;
if (*next == input->buf + input->len)
goto eof;
strbuf_addstr(&arg, *next);
*next += arg.len;
if (arg.len) {
if (get_sha1(arg.buf, sha1))
goto invalid;
} else if (flags & PARSE_SHA1_ALLOW_EMPTY) {
/* With -z, treat an empty value as all zeros: */
warning("%s %s: missing <newvalue>, treating as zero",
command, refname);
hashclr(sha1);
} else {
/*
* With -z, an empty non-required value means
* unspecified:
*/
ret = 1;
}
}
strbuf_release(&arg);
return ret;
invalid:
die(flags & PARSE_SHA1_OLD ?
"%s %s: invalid <oldvalue>: %s" :
"%s %s: invalid <newvalue>: %s",
command, refname, arg.buf);
eof:
die(flags & PARSE_SHA1_OLD ?
"%s %s: unexpected end of input when reading <oldvalue>" :
"%s %s: unexpected end of input when reading <newvalue>",
command, refname);
}
/*
* The following five parse_cmd_*() functions parse the corresponding
* command. In each case, next points at the character following the
* command name and the following space. They each return a pointer
* to the character terminating the command, and die with an
* explanatory message if there are any parsing problems. All of
* these functions handle either text or binary format input,
* depending on how line_termination is set.
*/
static const char *parse_cmd_update(struct strbuf *input, const char *next)
{
char *refname;
unsigned char new_sha1[20];
unsigned char old_sha1[20];
int have_old;
refname = parse_refname(input, &next);
if (!refname)
die("update: missing <ref>");
if (parse_next_sha1(input, &next, new_sha1, "update", refname,
PARSE_SHA1_ALLOW_EMPTY))
die("update %s: missing <newvalue>", refname);
have_old = !parse_next_sha1(input, &next, old_sha1, "update", refname,
PARSE_SHA1_OLD);
if (*next != line_termination)
die("update %s: extra input: %s", refname, next);
if (ref_transaction_update(transaction, refname, new_sha1, old_sha1,
update_flags, have_old, &err))
die("%s", err.buf);
update_flags = 0;
free(refname);
return next;
}
static const char *parse_cmd_create(struct strbuf *input, const char *next)
{
char *refname;
unsigned char new_sha1[20];
refname = parse_refname(input, &next);
if (!refname)
die("create: missing <ref>");
if (parse_next_sha1(input, &next, new_sha1, "create", refname, 0))
die("create %s: missing <newvalue>", refname);
if (is_null_sha1(new_sha1))
die("create %s: zero <newvalue>", refname);
if (*next != line_termination)
die("create %s: extra input: %s", refname, next);
ref_transaction_create(transaction, refname, new_sha1, update_flags);
update_flags = 0;
free(refname);
return next;
}
static const char *parse_cmd_delete(struct strbuf *input, const char *next)
{
char *refname;
unsigned char old_sha1[20];
int have_old;
refname = parse_refname(input, &next);
if (!refname)
die("delete: missing <ref>");
if (parse_next_sha1(input, &next, old_sha1, "delete", refname,
PARSE_SHA1_OLD)) {
have_old = 0;
} else {
if (is_null_sha1(old_sha1))
die("delete %s: zero <oldvalue>", refname);
have_old = 1;
}
if (*next != line_termination)
die("delete %s: extra input: %s", refname, next);
ref_transaction_delete(transaction, refname, old_sha1,
update_flags, have_old);
update_flags = 0;
free(refname);
return next;
}
static const char *parse_cmd_verify(struct strbuf *input, const char *next)
{
char *refname;
unsigned char new_sha1[20];
unsigned char old_sha1[20];
int have_old;
refname = parse_refname(input, &next);
if (!refname)
die("verify: missing <ref>");
if (parse_next_sha1(input, &next, old_sha1, "verify", refname,
PARSE_SHA1_OLD)) {
hashclr(new_sha1);
have_old = 0;
} else {
hashcpy(new_sha1, old_sha1);
have_old = 1;
}
if (*next != line_termination)
die("verify %s: extra input: %s", refname, next);
if (ref_transaction_update(transaction, refname, new_sha1, old_sha1,
update_flags, have_old, &err))
die("%s", err.buf);
update_flags = 0;
free(refname);
return next;
}
static const char *parse_cmd_option(struct strbuf *input, const char *next)
{
if (!strncmp(next, "no-deref", 8) && next[8] == line_termination)
update_flags |= REF_NODEREF;
else
die("option unknown: %s", next);
return next + 8;
}
static void update_refs_stdin(void)
{
struct strbuf input = STRBUF_INIT;
const char *next;
if (strbuf_read(&input, 0, 1000) < 0)
die_errno("could not read from stdin");
next = input.buf;
/* Read each line dispatch its command */
while (next < input.buf + input.len) {
if (*next == line_termination)
die("empty command in input");
else if (isspace(*next))
die("whitespace before command: %s", next);
else if (starts_with(next, "update "))
next = parse_cmd_update(&input, next + 7);
else if (starts_with(next, "create "))
next = parse_cmd_create(&input, next + 7);
else if (starts_with(next, "delete "))
next = parse_cmd_delete(&input, next + 7);
else if (starts_with(next, "verify "))
next = parse_cmd_verify(&input, next + 7);
else if (starts_with(next, "option "))
next = parse_cmd_option(&input, next + 7);
else
die("unknown command: %s", next);
next++;
}
strbuf_release(&input);
}
int cmd_update_ref(int argc, const char **argv, const char *prefix)
{
const char *refname, *oldval, *msg = NULL;
unsigned char sha1[20], oldsha1[20];
int delete = 0, no_deref = 0, read_stdin = 0, end_null = 0, flags = 0;
struct option options[] = {
OPT_STRING( 'm', NULL, &msg, N_("reason"), N_("reason of the update")),
OPT_BOOL('d', NULL, &delete, N_("delete the reference")),
OPT_BOOL( 0 , "no-deref", &no_deref,
N_("update <refname> not the one it points to")),
OPT_BOOL('z', NULL, &end_null, N_("stdin has NUL-terminated arguments")),
OPT_BOOL( 0 , "stdin", &read_stdin, N_("read updates from stdin")),
OPT_END(),
};
git_config(git_default_config, NULL);
argc = parse_options(argc, argv, prefix, options, git_update_ref_usage,
0);
if (msg && !*msg)
die("Refusing to perform update with empty message.");
if (read_stdin) {
transaction = ref_transaction_begin();
if (delete || no_deref || argc > 0)
usage_with_options(git_update_ref_usage, options);
if (end_null)
line_termination = '\0';
update_refs_stdin();
if (ref_transaction_commit(transaction, msg, &err))
die("%s", err.buf);
ref_transaction_free(transaction);
return 0;
}
if (end_null)
usage_with_options(git_update_ref_usage, options);
if (delete) {
if (argc < 1 || argc > 2)
usage_with_options(git_update_ref_usage, options);
refname = argv[0];
oldval = argv[1];
} else {
const char *value;
if (argc < 2 || argc > 3)
usage_with_options(git_update_ref_usage, options);
refname = argv[0];
value = argv[1];
oldval = argv[2];
if (get_sha1(value, sha1))
die("%s: not a valid SHA1", value);
}
hashclr(oldsha1); /* all-zero hash in case oldval is the empty string */
if (oldval && *oldval && get_sha1(oldval, oldsha1))
die("%s: not a valid old SHA1", oldval);
if (no_deref)
flags = REF_NODEREF;
if (delete)
return delete_ref(refname, oldval ? oldsha1 : NULL, flags);
else
return update_ref(msg, refname, sha1, oldval ? oldsha1 : NULL,
flags, UPDATE_REFS_DIE_ON_ERR);
}