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-rw-r--r--builtin/update-ref.c443
1 files changed, 443 insertions, 0 deletions
diff --git a/builtin/update-ref.c b/builtin/update-ref.c
new file mode 100644
index 0000000000..7f30d3a76f
--- /dev/null
+++ b/builtin/update-ref.c
@@ -0,0 +1,443 @@
+#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> [<old-val>]"),
+ N_("git update-ref [<options>] <refname> <new-val> [<old-val>]"),
+ N_("git update-ref [<options>] --stdin [-z]"),
+ NULL
+};
+
+static char line_termination = '\n';
+static int update_flags;
+static unsigned create_reflog_flag;
+static const char *msg;
+
+/*
+ * 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 ref_transaction *transaction,
+ struct strbuf *input, const char *next)
+{
+ struct strbuf err = STRBUF_INIT;
+ 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, have_old ? old_sha1 : NULL,
+ update_flags | create_reflog_flag,
+ msg, &err))
+ die("%s", err.buf);
+
+ update_flags = 0;
+ free(refname);
+ strbuf_release(&err);
+
+ return next;
+}
+
+static const char *parse_cmd_create(struct ref_transaction *transaction,
+ struct strbuf *input, const char *next)
+{
+ struct strbuf err = STRBUF_INIT;
+ 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);
+
+ if (ref_transaction_create(transaction, refname, new_sha1,
+ update_flags | create_reflog_flag,
+ msg, &err))
+ die("%s", err.buf);
+
+ update_flags = 0;
+ free(refname);
+ strbuf_release(&err);
+
+ return next;
+}
+
+static const char *parse_cmd_delete(struct ref_transaction *transaction,
+ struct strbuf *input, const char *next)
+{
+ struct strbuf err = STRBUF_INIT;
+ 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);
+
+ if (ref_transaction_delete(transaction, refname,
+ have_old ? old_sha1 : NULL,
+ update_flags, msg, &err))
+ die("%s", err.buf);
+
+ update_flags = 0;
+ free(refname);
+ strbuf_release(&err);
+
+ return next;
+}
+
+static const char *parse_cmd_verify(struct ref_transaction *transaction,
+ struct strbuf *input, const char *next)
+{
+ struct strbuf err = STRBUF_INIT;
+ char *refname;
+ unsigned char old_sha1[20];
+
+ 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(old_sha1);
+
+ if (*next != line_termination)
+ die("verify %s: extra input: %s", refname, next);
+
+ if (ref_transaction_verify(transaction, refname, old_sha1,
+ update_flags, &err))
+ die("%s", err.buf);
+
+ update_flags = 0;
+ free(refname);
+ strbuf_release(&err);
+
+ 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(struct ref_transaction *transaction)
+{
+ 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(transaction, &input, next + 7);
+ else if (starts_with(next, "create "))
+ next = parse_cmd_create(transaction, &input, next + 7);
+ else if (starts_with(next, "delete "))
+ next = parse_cmd_delete(transaction, &input, next + 7);
+ else if (starts_with(next, "verify "))
+ next = parse_cmd_verify(transaction, &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;
+ unsigned char sha1[20], oldsha1[20];
+ int delete = 0, no_deref = 0, read_stdin = 0, end_null = 0;
+ unsigned int flags = 0;
+ int create_reflog = 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_BOOL( 0 , "create-reflog", &create_reflog, N_("create a reflog")),
+ 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.");
+
+ create_reflog_flag = create_reflog ? REF_FORCE_CREATE_REFLOG : 0;
+
+ if (read_stdin) {
+ struct strbuf err = STRBUF_INIT;
+ struct ref_transaction *transaction;
+
+ transaction = ref_transaction_begin(&err);
+ if (!transaction)
+ die("%s", err.buf);
+ if (delete || no_deref || argc > 0)
+ usage_with_options(git_update_ref_usage, options);
+ if (end_null)
+ line_termination = '\0';
+ update_refs_stdin(transaction);
+ if (ref_transaction_commit(transaction, &err))
+ die("%s", err.buf);
+ ref_transaction_free(transaction);
+ strbuf_release(&err);
+ 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);
+ }
+
+ if (oldval) {
+ if (!*oldval)
+ /*
+ * The empty string implies that the reference
+ * must not already exist:
+ */
+ hashclr(oldsha1);
+ else if (get_sha1(oldval, oldsha1))
+ die("%s: not a valid old SHA1", oldval);
+ }
+
+ if (no_deref)
+ flags = REF_NODEREF;
+ if (delete)
+ /*
+ * For purposes of backwards compatibility, we treat
+ * NULL_SHA1 as "don't care" here:
+ */
+ return delete_ref(refname,
+ (oldval && !is_null_sha1(oldsha1)) ? oldsha1 : NULL,
+ flags);
+ else
+ return update_ref(msg, refname, sha1, oldval ? oldsha1 : NULL,
+ flags | create_reflog_flag,
+ UPDATE_REFS_DIE_ON_ERR);
+}