Move 'builtin-*' into a 'builtin/' subdirectory

This shrinks the top-level directory a bit, and makes it much more
pleasant to use auto-completion on the thing. Instead of

	[torvalds@nehalem git]$ em buil<tab>
	Display all 180 possibilities? (y or n)
	[torvalds@nehalem git]$ em builtin-sh
	builtin-shortlog.c     builtin-show-branch.c  builtin-show-ref.c
	builtin-shortlog.o     builtin-show-branch.o  builtin-show-ref.o
	[torvalds@nehalem git]$ em builtin-shor<tab>
	builtin-shortlog.c  builtin-shortlog.o
	[torvalds@nehalem git]$ em builtin-shortlog.c

you get

	[torvalds@nehalem git]$ em buil<tab>		[type]
	builtin/   builtin.h
	[torvalds@nehalem git]$ em builtin		[auto-completes to]
	[torvalds@nehalem git]$ em builtin/sh<tab>	[type]
	shortlog.c     shortlog.o     show-branch.c  show-branch.o  show-ref.c     show-ref.o
	[torvalds@nehalem git]$ em builtin/sho		[auto-completes to]
	[torvalds@nehalem git]$ em builtin/shor<tab>	[type]
	shortlog.c  shortlog.o
	[torvalds@nehalem git]$ em builtin/shortlog.c

which doesn't seem all that different, but not having that annoying
break in "Display all 180 possibilities?" is quite a relief.

NOTE! If you do this in a clean tree (no object files etc), or using an
editor that has auto-completion rules that ignores '*.o' files, you
won't see that annoying 'Display all 180 possibilities?' message - it
will just show the choices instead.  I think bash has some cut-off
around 100 choices or something.

So the reason I see this is that I'm using an odd editory, and thus
don't have the rules to cut down on auto-completion.  But you can
simulate that by using 'ls' instead, or something similar.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 460 insertions, 0 deletions

diff --git a/builtin/revert.c b/builtin/revert.c
new file mode 100644
index 0000000000..eff52687a8
--- /dev/null
+++ b/builtin/revert.c
@@ -0,0 +1,460 @@
+#include "cache.h"
+#include "builtin.h"
+#include "object.h"
+#include "commit.h"
+#include "tag.h"
+#include "wt-status.h"
+#include "run-command.h"
+#include "exec_cmd.h"
+#include "utf8.h"
+#include "parse-options.h"
+#include "cache-tree.h"
+#include "diff.h"
+#include "revision.h"
+#include "rerere.h"
+#include "merge-recursive.h"
+
+/*
+ * This implements the builtins revert and cherry-pick.
+ *
+ * Copyright (c) 2007 Johannes E. Schindelin
+ *
+ * Based on git-revert.sh, which is
+ *
+ * Copyright (c) 2005 Linus Torvalds
+ * Copyright (c) 2005 Junio C Hamano
+ */
+
+static const char * const revert_usage[] = {
+	"git revert [options] <commit-ish>",
+	NULL
+};
+
+static const char * const cherry_pick_usage[] = {
+	"git cherry-pick [options] <commit-ish>",
+	NULL
+};
+
+static int edit, no_replay, no_commit, mainline, signoff;
+static enum { REVERT, CHERRY_PICK } action;
+static struct commit *commit;
+static const char *commit_name;
+static int allow_rerere_auto;
+
+static const char *me;
+
+#define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
+
+static void parse_args(int argc, const char **argv)
+{
+	const char * const * usage_str =
+		action == REVERT ?  revert_usage : cherry_pick_usage;
+	unsigned char sha1[20];
+	int noop;
+	struct option options[] = {
+		OPT_BOOLEAN('n', "no-commit", &no_commit, "don't automatically commit"),
+		OPT_BOOLEAN('e', "edit", &edit, "edit the commit message"),
+		OPT_BOOLEAN('x', NULL, &no_replay, "append commit name when cherry-picking"),
+		OPT_BOOLEAN('r', NULL, &noop, "no-op (backward compatibility)"),
+		OPT_BOOLEAN('s', "signoff", &signoff, "add Signed-off-by:"),
+		OPT_INTEGER('m', "mainline", &mainline, "parent number"),
+		OPT_RERERE_AUTOUPDATE(&allow_rerere_auto),
+		OPT_END(),
+	};
+
+	if (parse_options(argc, argv, NULL, options, usage_str, 0) != 1)
+		usage_with_options(usage_str, options);
+
+	commit_name = argv[0];
+	if (get_sha1(commit_name, sha1))
+		die ("Cannot find '%s'", commit_name);
+	commit = lookup_commit_reference(sha1);
+	if (!commit)
+		exit(1);
+}
+
+static char *get_oneline(const char *message)
+{
+	char *result;
+	const char *p = message, *abbrev, *eol;
+	int abbrev_len, oneline_len;
+
+	if (!p)
+		die ("Could not read commit message of %s",
+				sha1_to_hex(commit->object.sha1));
+	while (*p && (*p != '\n' || p[1] != '\n'))
+		p++;
+
+	if (*p) {
+		p += 2;
+		for (eol = p + 1; *eol && *eol != '\n'; eol++)
+			; /* do nothing */
+	} else
+		eol = p;
+	abbrev = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
+	abbrev_len = strlen(abbrev);
+	oneline_len = eol - p;
+	result = xmalloc(abbrev_len + 5 + oneline_len);
+	memcpy(result, abbrev, abbrev_len);
+	memcpy(result + abbrev_len, "... ", 4);
+	memcpy(result + abbrev_len + 4, p, oneline_len);
+	result[abbrev_len + 4 + oneline_len] = '\0';
+	return result;
+}
+
+static char *get_encoding(const char *message)
+{
+	const char *p = message, *eol;
+
+	if (!p)
+		die ("Could not read commit message of %s",
+				sha1_to_hex(commit->object.sha1));
+	while (*p && *p != '\n') {
+		for (eol = p + 1; *eol && *eol != '\n'; eol++)
+			; /* do nothing */
+		if (!prefixcmp(p, "encoding ")) {
+			char *result = xmalloc(eol - 8 - p);
+			strlcpy(result, p + 9, eol - 8 - p);
+			return result;
+		}
+		p = eol;
+		if (*p == '\n')
+			p++;
+	}
+	return NULL;
+}
+
+static struct lock_file msg_file;
+static int msg_fd;
+
+static void add_to_msg(const char *string)
+{
+	int len = strlen(string);
+	if (write_in_full(msg_fd, string, len) < 0)
+		die_errno ("Could not write to MERGE_MSG");
+}
+
+static void add_message_to_msg(const char *message)
+{
+	const char *p = message;
+	while (*p && (*p != '\n' || p[1] != '\n'))
+		p++;
+
+	if (!*p)
+		add_to_msg(sha1_to_hex(commit->object.sha1));
+
+	p += 2;
+	add_to_msg(p);
+	return;
+}
+
+static void set_author_ident_env(const char *message)
+{
+	const char *p = message;
+	if (!p)
+		die ("Could not read commit message of %s",
+				sha1_to_hex(commit->object.sha1));
+	while (*p && *p != '\n') {
+		const char *eol;
+
+		for (eol = p; *eol && *eol != '\n'; eol++)
+			; /* do nothing */
+		if (!prefixcmp(p, "author ")) {
+			char *line, *pend, *email, *timestamp;
+
+			p += 7;
+			line = xmemdupz(p, eol - p);
+			email = strchr(line, '<');
+			if (!email)
+				die ("Could not extract author email from %s",
+					sha1_to_hex(commit->object.sha1));
+			if (email == line)
+				pend = line;
+			else
+				for (pend = email; pend != line + 1 &&
+						isspace(pend[-1]); pend--);
+					; /* do nothing */
+			*pend = '\0';
+			email++;
+			timestamp = strchr(email, '>');
+			if (!timestamp)
+				die ("Could not extract author time from %s",
+					sha1_to_hex(commit->object.sha1));
+			*timestamp = '\0';
+			for (timestamp++; *timestamp && isspace(*timestamp);
+					timestamp++)
+				; /* do nothing */
+			setenv("GIT_AUTHOR_NAME", line, 1);
+			setenv("GIT_AUTHOR_EMAIL", email, 1);
+			setenv("GIT_AUTHOR_DATE", timestamp, 1);
+			free(line);
+			return;
+		}
+		p = eol;
+		if (*p == '\n')
+			p++;
+	}
+	die ("No author information found in %s",
+			sha1_to_hex(commit->object.sha1));
+}
+
+static char *help_msg(const char *name)
+{
+	struct strbuf helpbuf = STRBUF_INIT;
+	char *msg = getenv("GIT_CHERRY_PICK_HELP");
+
+	if (msg)
+		return msg;
+
+	strbuf_addstr(&helpbuf, "  After resolving the conflicts,\n"
+		"mark the corrected paths with 'git add <paths>' or 'git rm <paths>'\n"
+		"and commit the result");
+
+	if (action == CHERRY_PICK) {
+		strbuf_addf(&helpbuf, " with: \n"
+			"\n"
+			"        git commit -c %s\n",
+			name);
+	}
+	else
+		strbuf_addch(&helpbuf, '.');
+	return strbuf_detach(&helpbuf, NULL);
+}
+
+static struct tree *empty_tree(void)
+{
+	struct tree *tree = xcalloc(1, sizeof(struct tree));
+
+	tree->object.parsed = 1;
+	tree->object.type = OBJ_TREE;
+	pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
+	return tree;
+}
+
+static NORETURN void die_dirty_index(const char *me)
+{
+	if (read_cache_unmerged()) {
+		die_resolve_conflict(me);
+	} else {
+		if (advice_commit_before_merge)
+			die("Your local changes would be overwritten by %s.\n"
+			    "Please, commit your changes or stash them to proceed.", me);
+		else
+			die("Your local changes would be overwritten by %s.\n", me);
+	}
+}
+
+static int revert_or_cherry_pick(int argc, const char **argv)
+{
+	unsigned char head[20];
+	struct commit *base, *next, *parent;
+	int i, index_fd, clean;
+	char *oneline, *reencoded_message = NULL;
+	const char *message, *encoding;
+	char *defmsg = git_pathdup("MERGE_MSG");
+	struct merge_options o;
+	struct tree *result, *next_tree, *base_tree, *head_tree;
+	static struct lock_file index_lock;
+
+	git_config(git_default_config, NULL);
+	me = action == REVERT ? "revert" : "cherry-pick";
+	setenv(GIT_REFLOG_ACTION, me, 0);
+	parse_args(argc, argv);
+
+	/* this is copied from the shell script, but it's never triggered... */
+	if (action == REVERT && !no_replay)
+		die("revert is incompatible with replay");
+
+	if (read_cache() < 0)
+		die("git %s: failed to read the index", me);
+	if (no_commit) {
+		/*
+		 * We do not intend to commit immediately.  We just want to
+		 * merge the differences in, so let's compute the tree
+		 * that represents the "current" state for merge-recursive
+		 * to work on.
+		 */
+		if (write_cache_as_tree(head, 0, NULL))
+			die ("Your index file is unmerged.");
+	} else {
+		if (get_sha1("HEAD", head))
+			die ("You do not have a valid HEAD");
+		if (index_differs_from("HEAD", 0))
+			die_dirty_index(me);
+	}
+	discard_cache();
+
+	index_fd = hold_locked_index(&index_lock, 1);
+
+	if (!commit->parents) {
+		if (action == REVERT)
+			die ("Cannot revert a root commit");
+		parent = NULL;
+	}
+	else if (commit->parents->next) {
+		/* Reverting or cherry-picking a merge commit */
+		int cnt;
+		struct commit_list *p;
+
+		if (!mainline)
+			die("Commit %s is a merge but no -m option was given.",
+			    sha1_to_hex(commit->object.sha1));
+
+		for (cnt = 1, p = commit->parents;
+		     cnt != mainline && p;
+		     cnt++)
+			p = p->next;
+		if (cnt != mainline || !p)
+			die("Commit %s does not have parent %d",
+			    sha1_to_hex(commit->object.sha1), mainline);
+		parent = p->item;
+	} else if (0 < mainline)
+		die("Mainline was specified but commit %s is not a merge.",
+		    sha1_to_hex(commit->object.sha1));
+	else
+		parent = commit->parents->item;
+
+	if (!(message = commit->buffer))
+		die ("Cannot get commit message for %s",
+				sha1_to_hex(commit->object.sha1));
+
+	if (parent && parse_commit(parent) < 0)
+		die("%s: cannot parse parent commit %s",
+		    me, sha1_to_hex(parent->object.sha1));
+
+	/*
+	 * "commit" is an existing commit.  We would want to apply
+	 * the difference it introduces since its first parent "prev"
+	 * on top of the current HEAD if we are cherry-pick.  Or the
+	 * reverse of it if we are revert.
+	 */
+
+	msg_fd = hold_lock_file_for_update(&msg_file, defmsg,
+					   LOCK_DIE_ON_ERROR);
+
+	encoding = get_encoding(message);
+	if (!encoding)
+		encoding = "UTF-8";
+	if (!git_commit_encoding)
+		git_commit_encoding = "UTF-8";
+	if ((reencoded_message = reencode_string(message,
+					git_commit_encoding, encoding)))
+		message = reencoded_message;
+
+	oneline = get_oneline(message);
+
+	if (action == REVERT) {
+		char *oneline_body = strchr(oneline, ' ');
+
+		base = commit;
+		next = parent;
+		add_to_msg("Revert \"");
+		add_to_msg(oneline_body + 1);
+		add_to_msg("\"\n\nThis reverts commit ");
+		add_to_msg(sha1_to_hex(commit->object.sha1));
+
+		if (commit->parents->next) {
+			add_to_msg(", reversing\nchanges made to ");
+			add_to_msg(sha1_to_hex(parent->object.sha1));
+		}
+		add_to_msg(".\n");
+	} else {
+		base = parent;
+		next = commit;
+		set_author_ident_env(message);
+		add_message_to_msg(message);
+		if (no_replay) {
+			add_to_msg("(cherry picked from commit ");
+			add_to_msg(sha1_to_hex(commit->object.sha1));
+			add_to_msg(")\n");
+		}
+	}
+
+	read_cache();
+	init_merge_options(&o);
+	o.branch1 = "HEAD";
+	o.branch2 = oneline;
+
+	head_tree = parse_tree_indirect(head);
+	next_tree = next ? next->tree : empty_tree();
+	base_tree = base ? base->tree : empty_tree();
+
+	clean = merge_trees(&o,
+			    head_tree,
+			    next_tree, base_tree, &result);
+
+	if (active_cache_changed &&
+	    (write_cache(index_fd, active_cache, active_nr) ||
+	     commit_locked_index(&index_lock)))
+		die("%s: Unable to write new index file", me);
+	rollback_lock_file(&index_lock);
+
+	if (!clean) {
+		add_to_msg("\nConflicts:\n\n");
+		for (i = 0; i < active_nr;) {
+			struct cache_entry *ce = active_cache[i++];
+			if (ce_stage(ce)) {
+				add_to_msg("\t");
+				add_to_msg(ce->name);
+				add_to_msg("\n");
+				while (i < active_nr && !strcmp(ce->name,
+						active_cache[i]->name))
+					i++;
+			}
+		}
+		if (commit_lock_file(&msg_file) < 0)
+			die ("Error wrapping up %s", defmsg);
+		fprintf(stderr, "Automatic %s failed.%s\n",
+			me, help_msg(commit_name));
+		rerere(allow_rerere_auto);
+		exit(1);
+	}
+	if (commit_lock_file(&msg_file) < 0)
+		die ("Error wrapping up %s", defmsg);
+	fprintf(stderr, "Finished one %s.\n", me);
+
+	/*
+	 *
+	 * If we are cherry-pick, and if the merge did not result in
+	 * hand-editing, we will hit this commit and inherit the original
+	 * author date and name.
+	 * If we are revert, or if our cherry-pick results in a hand merge,
+	 * we had better say that the current user is responsible for that.
+	 */
+
+	if (!no_commit) {
+		/* 6 is max possible length of our args array including NULL */
+		const char *args[6];
+		int i = 0;
+		args[i++] = "commit";
+		args[i++] = "-n";
+		if (signoff)
+			args[i++] = "-s";
+		if (!edit) {
+			args[i++] = "-F";
+			args[i++] = defmsg;
+		}
+		args[i] = NULL;
+		return execv_git_cmd(args);
+	}
+	free(reencoded_message);
+	free(defmsg);
+
+	return 0;
+}
+
+int cmd_revert(int argc, const char **argv, const char *prefix)
+{
+	if (isatty(0))
+		edit = 1;
+	no_replay = 1;
+	action = REVERT;
+	return revert_or_cherry_pick(argc, argv);
+}
+
+int cmd_cherry_pick(int argc, const char **argv, const char *prefix)
+{
+	no_replay = 0;
+	action = CHERRY_PICK;
+	return revert_or_cherry_pick(argc, argv);
+}