1 files changed, 396 insertions, 11 deletions

diff --git a/builtin/update-ref.c b/builtin/update-ref.c
index 51d2684859..04dd00f734 100644
--- a/builtin/update-ref.c
+++ b/builtin/update-ref.c
@@ -2,23 +2,370 @@
 #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>] -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, *msg = NULL;
+	const char *refname, *oldval;
 	unsigned char sha1[20], oldsha1[20];
-	int delete = 0, no_deref = 0, flags = 0;
+	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_BOOLEAN('d', NULL, &delete, N_("delete the reference")),
-		OPT_BOOLEAN( 0 , "no-deref", &no_deref,
+		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_reflog")),
 		OPT_END(),
 	};
 
@@ -28,6 +375,30 @@ int cmd_update_ref(int argc, const char **argv, const char *prefix)
 	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);
@@ -44,15 +415,29 @@ int cmd_update_ref(int argc, const char **argv, const char *prefix)
 			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 (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)
-		return delete_ref(refname, oldval ? oldsha1 : NULL, flags);
+		/*
+		 * 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, DIE_ON_ERR);
+				  flags | create_reflog_flag,
+				  UPDATE_REFS_DIE_ON_ERR);
 }