Make git-update-index a builtin

Signed-off-by: Lukas Sandström <lukass@etek.chalmers.se>
Signed-off-by: Junio C Hamano <junkio@cox.net>
diff --git a/builtin-update-index.c b/builtin-update-index.c
new file mode 100644
index 0000000..325cd09
--- /dev/null
+++ b/builtin-update-index.c
@@ -0,0 +1,658 @@
+/*
+ * GIT - The information manager from hell
+ *
+ * Copyright (C) Linus Torvalds, 2005
+ */
+#include "cache.h"
+#include "strbuf.h"
+#include "quote.h"
+#include "cache-tree.h"
+#include "tree-walk.h"
+#include "builtin.h"
+
+/*
+ * Default to not allowing changes to the list of files. The
+ * tool doesn't actually care, but this makes it harder to add
+ * files to the revision control by mistake by doing something
+ * like "git-update-index *" and suddenly having all the object
+ * files be revision controlled.
+ */
+static int allow_add;
+static int allow_remove;
+static int allow_replace;
+static int info_only;
+static int force_remove;
+static int verbose;
+static int mark_valid_only = 0;
+#define MARK_VALID 1
+#define UNMARK_VALID 2
+
+static void report(const char *fmt, ...)
+{
+	va_list vp;
+
+	if (!verbose)
+		return;
+
+	va_start(vp, fmt);
+	vprintf(fmt, vp);
+	putchar('\n');
+	va_end(vp);
+}
+
+static int mark_valid(const char *path)
+{
+	int namelen = strlen(path);
+	int pos = cache_name_pos(path, namelen);
+	if (0 <= pos) {
+		switch (mark_valid_only) {
+		case MARK_VALID:
+			active_cache[pos]->ce_flags |= htons(CE_VALID);
+			break;
+		case UNMARK_VALID:
+			active_cache[pos]->ce_flags &= ~htons(CE_VALID);
+			break;
+		}
+		cache_tree_invalidate_path(active_cache_tree, path);
+		active_cache_changed = 1;
+		return 0;
+	}
+	return -1;
+}
+
+static int add_file_to_cache(const char *path)
+{
+	int size, namelen, option, status;
+	struct cache_entry *ce;
+	struct stat st;
+
+	status = lstat(path, &st);
+
+	/* We probably want to do this in remove_file_from_cache() and
+	 * add_cache_entry() instead...
+	 */
+	cache_tree_invalidate_path(active_cache_tree, path);
+
+	if (status < 0 || S_ISDIR(st.st_mode)) {
+		/* When we used to have "path" and now we want to add
+		 * "path/file", we need a way to remove "path" before
+		 * being able to add "path/file".  However,
+		 * "git-update-index --remove path" would not work.
+		 * --force-remove can be used but this is more user
+		 * friendly, especially since we can do the opposite
+		 * case just fine without --force-remove.
+		 */
+		if (status == 0 || (errno == ENOENT || errno == ENOTDIR)) {
+			if (allow_remove) {
+				if (remove_file_from_cache(path))
+					return error("%s: cannot remove from the index",
+					             path);
+				else
+					return 0;
+			} else if (status < 0) {
+				return error("%s: does not exist and --remove not passed",
+				             path);
+			}
+		}
+		if (0 == status)
+			return error("%s: is a directory - add files inside instead",
+			             path);
+		else
+			return error("lstat(\"%s\"): %s", path,
+				     strerror(errno));
+	}
+
+	namelen = strlen(path);
+	size = cache_entry_size(namelen);
+	ce = xcalloc(1, size);
+	memcpy(ce->name, path, namelen);
+	ce->ce_flags = htons(namelen);
+	fill_stat_cache_info(ce, &st);
+
+	ce->ce_mode = create_ce_mode(st.st_mode);
+	if (!trust_executable_bit) {
+		/* If there is an existing entry, pick the mode bits
+		 * from it.
+		 */
+		int pos = cache_name_pos(path, namelen);
+		if (0 <= pos)
+			ce->ce_mode = active_cache[pos]->ce_mode;
+	}
+
+	if (index_path(ce->sha1, path, &st, !info_only))
+		return -1;
+	option = allow_add ? ADD_CACHE_OK_TO_ADD : 0;
+	option |= allow_replace ? ADD_CACHE_OK_TO_REPLACE : 0;
+	if (add_cache_entry(ce, option))
+		return error("%s: cannot add to the index - missing --add option?",
+			     path);
+	return 0;
+}
+
+static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
+			 const char *path, int stage)
+{
+	int size, len, option;
+	struct cache_entry *ce;
+
+	if (!verify_path(path))
+		return -1;
+
+	len = strlen(path);
+	size = cache_entry_size(len);
+	ce = xcalloc(1, size);
+
+	memcpy(ce->sha1, sha1, 20);
+	memcpy(ce->name, path, len);
+	ce->ce_flags = create_ce_flags(len, stage);
+	ce->ce_mode = create_ce_mode(mode);
+	if (assume_unchanged)
+		ce->ce_flags |= htons(CE_VALID);
+	option = allow_add ? ADD_CACHE_OK_TO_ADD : 0;
+	option |= allow_replace ? ADD_CACHE_OK_TO_REPLACE : 0;
+	if (add_cache_entry(ce, option))
+		return error("%s: cannot add to the index - missing --add option?",
+			     path);
+	report("add '%s'", path);
+	cache_tree_invalidate_path(active_cache_tree, path);
+	return 0;
+}
+
+static void chmod_path(int flip, const char *path)
+{
+	int pos;
+	struct cache_entry *ce;
+	unsigned int mode;
+
+	pos = cache_name_pos(path, strlen(path));
+	if (pos < 0)
+		goto fail;
+	ce = active_cache[pos];
+	mode = ntohl(ce->ce_mode);
+	if (!S_ISREG(mode))
+		goto fail;
+	switch (flip) {
+	case '+':
+		ce->ce_mode |= htonl(0111); break;
+	case '-':
+		ce->ce_mode &= htonl(~0111); break;
+	default:
+		goto fail;
+	}
+	cache_tree_invalidate_path(active_cache_tree, path);
+	active_cache_changed = 1;
+	report("chmod %cx '%s'", flip, path);
+	return;
+ fail:
+	die("git-update-index: cannot chmod %cx '%s'", flip, path);
+}
+
+static void update_one(const char *path, const char *prefix, int prefix_length)
+{
+	const char *p = prefix_path(prefix, prefix_length, path);
+	if (!verify_path(p)) {
+		fprintf(stderr, "Ignoring path %s\n", path);
+		goto free_return;
+	}
+	if (mark_valid_only) {
+		if (mark_valid(p))
+			die("Unable to mark file %s", path);
+		goto free_return;
+	}
+	cache_tree_invalidate_path(active_cache_tree, path);
+
+	if (force_remove) {
+		if (remove_file_from_cache(p))
+			die("git-update-index: unable to remove %s", path);
+		report("remove '%s'", path);
+		goto free_return;
+	}
+	if (add_file_to_cache(p))
+		die("Unable to process file %s", path);
+	report("add '%s'", path);
+ free_return:
+	if (p < path || p > path + strlen(path))
+		free((char*)p);
+}
+
+static void read_index_info(int line_termination)
+{
+	struct strbuf buf;
+	strbuf_init(&buf);
+	while (1) {
+		char *ptr, *tab;
+		char *path_name;
+		unsigned char sha1[20];
+		unsigned int mode;
+		int stage;
+
+		/* This reads lines formatted in one of three formats:
+		 *
+		 * (1) mode         SP sha1          TAB path
+		 * The first format is what "git-apply --index-info"
+		 * reports, and used to reconstruct a partial tree
+		 * that is used for phony merge base tree when falling
+		 * back on 3-way merge.
+		 *
+		 * (2) mode SP type SP sha1          TAB path
+		 * The second format is to stuff git-ls-tree output
+		 * into the index file.
+		 *
+		 * (3) mode         SP sha1 SP stage TAB path
+		 * This format is to put higher order stages into the
+		 * index file and matches git-ls-files --stage output.
+		 */
+		read_line(&buf, stdin, line_termination);
+		if (buf.eof)
+			break;
+
+		mode = strtoul(buf.buf, &ptr, 8);
+		if (ptr == buf.buf || *ptr != ' ')
+			goto bad_line;
+
+		tab = strchr(ptr, '\t');
+		if (!tab || tab - ptr < 41)
+			goto bad_line;
+
+		if (tab[-2] == ' ' && '0' <= tab[-1] && tab[-1] <= '3') {
+			stage = tab[-1] - '0';
+			ptr = tab + 1; /* point at the head of path */
+			tab = tab - 2; /* point at tail of sha1 */
+		}
+		else {
+			stage = 0;
+			ptr = tab + 1; /* point at the head of path */
+		}
+
+		if (get_sha1_hex(tab - 40, sha1) || tab[-41] != ' ')
+			goto bad_line;
+
+		if (line_termination && ptr[0] == '"')
+			path_name = unquote_c_style(ptr, NULL);
+		else
+			path_name = ptr;
+
+		if (!verify_path(path_name)) {
+			fprintf(stderr, "Ignoring path %s\n", path_name);
+			if (path_name != ptr)
+				free(path_name);
+			continue;
+		}
+		cache_tree_invalidate_path(active_cache_tree, path_name);
+
+		if (!mode) {
+			/* mode == 0 means there is no such path -- remove */
+			if (remove_file_from_cache(path_name))
+				die("git-update-index: unable to remove %s",
+				    ptr);
+		}
+		else {
+			/* mode ' ' sha1 '\t' name
+			 * ptr[-1] points at tab,
+			 * ptr[-41] is at the beginning of sha1
+			 */
+			ptr[-42] = ptr[-1] = 0;
+			if (add_cacheinfo(mode, sha1, path_name, stage))
+				die("git-update-index: unable to update %s",
+				    path_name);
+		}
+		if (path_name != ptr)
+			free(path_name);
+		continue;
+
+	bad_line:
+		die("malformed index info %s", buf.buf);
+	}
+}
+
+static const char update_index_usage[] =
+"git-update-index [-q] [--add] [--replace] [--remove] [--unmerged] [--refresh] [--really-refresh] [--cacheinfo] [--chmod=(+|-)x] [--assume-unchanged] [--info-only] [--force-remove] [--stdin] [--index-info] [--unresolve] [--again] [--ignore-missing] [-z] [--verbose] [--] <file>...";
+
+static unsigned char head_sha1[20];
+static unsigned char merge_head_sha1[20];
+
+static struct cache_entry *read_one_ent(const char *which,
+					unsigned char *ent, const char *path,
+					int namelen, int stage)
+{
+	unsigned mode;
+	unsigned char sha1[20];
+	int size;
+	struct cache_entry *ce;
+
+	if (get_tree_entry(ent, path, sha1, &mode)) {
+		if (which)
+			error("%s: not in %s branch.", path, which);
+		return NULL;
+	}
+	if (mode == S_IFDIR) {
+		if (which)
+			error("%s: not a blob in %s branch.", path, which);
+		return NULL;
+	}
+	size = cache_entry_size(namelen);
+	ce = xcalloc(1, size);
+
+	memcpy(ce->sha1, sha1, 20);
+	memcpy(ce->name, path, namelen);
+	ce->ce_flags = create_ce_flags(namelen, stage);
+	ce->ce_mode = create_ce_mode(mode);
+	return ce;
+}
+
+static int unresolve_one(const char *path)
+{
+	int namelen = strlen(path);
+	int pos;
+	int ret = 0;
+	struct cache_entry *ce_2 = NULL, *ce_3 = NULL;
+
+	/* See if there is such entry in the index. */
+	pos = cache_name_pos(path, namelen);
+	if (pos < 0) {
+		/* If there isn't, either it is unmerged, or
+		 * resolved as "removed" by mistake.  We do not
+		 * want to do anything in the former case.
+		 */
+		pos = -pos-1;
+		if (pos < active_nr) {
+			struct cache_entry *ce = active_cache[pos];
+			if (ce_namelen(ce) == namelen &&
+			    !memcmp(ce->name, path, namelen)) {
+				fprintf(stderr,
+					"%s: skipping still unmerged path.\n",
+					path);
+				goto free_return;
+			}
+		}
+	}
+
+	/* Grab blobs from given path from HEAD and MERGE_HEAD,
+	 * stuff HEAD version in stage #2,
+	 * stuff MERGE_HEAD version in stage #3.
+	 */
+	ce_2 = read_one_ent("our", head_sha1, path, namelen, 2);
+	ce_3 = read_one_ent("their", merge_head_sha1, path, namelen, 3);
+
+	if (!ce_2 || !ce_3) {
+		ret = -1;
+		goto free_return;
+	}
+	if (!memcmp(ce_2->sha1, ce_3->sha1, 20) &&
+	    ce_2->ce_mode == ce_3->ce_mode) {
+		fprintf(stderr, "%s: identical in both, skipping.\n",
+			path);
+		goto free_return;
+	}
+
+	cache_tree_invalidate_path(active_cache_tree, path);
+	remove_file_from_cache(path);
+	if (add_cache_entry(ce_2, ADD_CACHE_OK_TO_ADD)) {
+		error("%s: cannot add our version to the index.", path);
+		ret = -1;
+		goto free_return;
+	}
+	if (!add_cache_entry(ce_3, ADD_CACHE_OK_TO_ADD))
+		return 0;
+	error("%s: cannot add their version to the index.", path);
+	ret = -1;
+ free_return:
+	free(ce_2);
+	free(ce_3);
+	return ret;
+}
+
+static void read_head_pointers(void)
+{
+	if (read_ref(git_path("HEAD"), head_sha1))
+		die("No HEAD -- no initial commit yet?\n");
+	if (read_ref(git_path("MERGE_HEAD"), merge_head_sha1)) {
+		fprintf(stderr, "Not in the middle of a merge.\n");
+		exit(0);
+	}
+}
+
+static int do_unresolve(int ac, const char **av,
+			const char *prefix, int prefix_length)
+{
+	int i;
+	int err = 0;
+
+	/* Read HEAD and MERGE_HEAD; if MERGE_HEAD does not exist, we
+	 * are not doing a merge, so exit with success status.
+	 */
+	read_head_pointers();
+
+	for (i = 1; i < ac; i++) {
+		const char *arg = av[i];
+		const char *p = prefix_path(prefix, prefix_length, arg);
+		err |= unresolve_one(p);
+		if (p < arg || p > arg + strlen(arg))
+			free((char*)p);
+	}
+	return err;
+}
+
+static int do_reupdate(int ac, const char **av,
+		       const char *prefix, int prefix_length)
+{
+	/* Read HEAD and run update-index on paths that are
+	 * merged and already different between index and HEAD.
+	 */
+	int pos;
+	int has_head = 1;
+	const char **pathspec = get_pathspec(prefix, av + 1);
+
+	if (read_ref(git_path("HEAD"), head_sha1))
+		/* If there is no HEAD, that means it is an initial
+		 * commit.  Update everything in the index.
+		 */
+		has_head = 0;
+ redo:
+	for (pos = 0; pos < active_nr; pos++) {
+		struct cache_entry *ce = active_cache[pos];
+		struct cache_entry *old = NULL;
+		int save_nr;
+
+		if (ce_stage(ce) || !ce_path_match(ce, pathspec))
+			continue;
+		if (has_head)
+			old = read_one_ent(NULL, head_sha1,
+					   ce->name, ce_namelen(ce), 0);
+		if (old && ce->ce_mode == old->ce_mode &&
+		    !memcmp(ce->sha1, old->sha1, 20)) {
+			free(old);
+			continue; /* unchanged */
+		}
+		/* Be careful.  The working tree may not have the
+		 * path anymore, in which case, under 'allow_remove',
+		 * or worse yet 'allow_replace', active_nr may decrease.
+		 */
+		save_nr = active_nr;
+		update_one(ce->name + prefix_length, prefix, prefix_length);
+		if (save_nr != active_nr)
+			goto redo;
+	}
+	return 0;
+}
+
+int cmd_update_index(int argc, const char **argv, char **envp)
+{
+	int i, newfd, entries, has_errors = 0, line_termination = '\n';
+	int allow_options = 1;
+	int read_from_stdin = 0;
+	const char *prefix = setup_git_directory();
+	int prefix_length = prefix ? strlen(prefix) : 0;
+	char set_executable_bit = 0;
+	unsigned int refresh_flags = 0;
+	struct lock_file *lock_file;
+
+	git_config(git_default_config);
+
+	/* We can't free this memory, it becomes part of a linked list parsed atexit() */
+	lock_file = xmalloc(sizeof(struct lock_file));
+
+	newfd = hold_lock_file_for_update(lock_file, get_index_file());
+	if (newfd < 0)
+		die("unable to create new cachefile");
+
+	entries = read_cache();
+	if (entries < 0)
+		die("cache corrupted");
+
+	for (i = 1 ; i < argc; i++) {
+		const char *path = argv[i];
+
+		if (allow_options && *path == '-') {
+			if (!strcmp(path, "--")) {
+				allow_options = 0;
+				continue;
+			}
+			if (!strcmp(path, "-q")) {
+				refresh_flags |= REFRESH_QUIET;
+				continue;
+			}
+			if (!strcmp(path, "--add")) {
+				allow_add = 1;
+				continue;
+			}
+			if (!strcmp(path, "--replace")) {
+				allow_replace = 1;
+				continue;
+			}
+			if (!strcmp(path, "--remove")) {
+				allow_remove = 1;
+				continue;
+			}
+			if (!strcmp(path, "--unmerged")) {
+				refresh_flags |= REFRESH_UNMERGED;
+				continue;
+			}
+			if (!strcmp(path, "--refresh")) {
+				has_errors |= refresh_cache(refresh_flags);
+				continue;
+			}
+			if (!strcmp(path, "--really-refresh")) {
+				has_errors |= refresh_cache(REFRESH_REALLY | refresh_flags);
+				continue;
+			}
+			if (!strcmp(path, "--cacheinfo")) {
+				unsigned char sha1[20];
+				unsigned int mode;
+
+				if (i+3 >= argc)
+					die("git-update-index: --cacheinfo <mode> <sha1> <path>");
+
+				if ((sscanf(argv[i+1], "%o", &mode) != 1) ||
+				    get_sha1_hex(argv[i+2], sha1) ||
+				    add_cacheinfo(mode, sha1, argv[i+3], 0))
+					die("git-update-index: --cacheinfo"
+					    " cannot add %s", argv[i+3]);
+				i += 3;
+				continue;
+			}
+			if (!strcmp(path, "--chmod=-x") ||
+			    !strcmp(path, "--chmod=+x")) {
+				if (argc <= i+1)
+					die("git-update-index: %s <path>", path);
+				set_executable_bit = path[8];
+				continue;
+			}
+			if (!strcmp(path, "--assume-unchanged")) {
+				mark_valid_only = MARK_VALID;
+				continue;
+			}
+			if (!strcmp(path, "--no-assume-unchanged")) {
+				mark_valid_only = UNMARK_VALID;
+				continue;
+			}
+			if (!strcmp(path, "--info-only")) {
+				info_only = 1;
+				continue;
+			}
+			if (!strcmp(path, "--force-remove")) {
+				force_remove = 1;
+				continue;
+			}
+			if (!strcmp(path, "-z")) {
+				line_termination = 0;
+				continue;
+			}
+			if (!strcmp(path, "--stdin")) {
+				if (i != argc - 1)
+					die("--stdin must be at the end");
+				read_from_stdin = 1;
+				break;
+			}
+			if (!strcmp(path, "--index-info")) {
+				if (i != argc - 1)
+					die("--index-info must be at the end");
+				allow_add = allow_replace = allow_remove = 1;
+				read_index_info(line_termination);
+				break;
+			}
+			if (!strcmp(path, "--unresolve")) {
+				has_errors = do_unresolve(argc - i, argv + i,
+							  prefix, prefix_length);
+				if (has_errors)
+					active_cache_changed = 0;
+				goto finish;
+			}
+			if (!strcmp(path, "--again")) {
+				has_errors = do_reupdate(argc - i, argv + i,
+							 prefix, prefix_length);
+				if (has_errors)
+					active_cache_changed = 0;
+				goto finish;
+			}
+			if (!strcmp(path, "--ignore-missing")) {
+				refresh_flags |= REFRESH_IGNORE_MISSING;
+				continue;
+			}
+			if (!strcmp(path, "--verbose")) {
+				verbose = 1;
+				continue;
+			}
+			if (!strcmp(path, "-h") || !strcmp(path, "--help"))
+				usage(update_index_usage);
+			die("unknown option %s", path);
+		}
+		update_one(path, prefix, prefix_length);
+		if (set_executable_bit)
+			chmod_path(set_executable_bit, path);
+	}
+	if (read_from_stdin) {
+		struct strbuf buf;
+		strbuf_init(&buf);
+		while (1) {
+			char *path_name;
+			const char *p;
+			read_line(&buf, stdin, line_termination);
+			if (buf.eof)
+				break;
+			if (line_termination && buf.buf[0] == '"')
+				path_name = unquote_c_style(buf.buf, NULL);
+			else
+				path_name = buf.buf;
+			p = prefix_path(prefix, prefix_length, path_name);
+			update_one(p, NULL, 0);
+			if (set_executable_bit)
+				chmod_path(set_executable_bit, p);
+			if (p < path_name || p > path_name + strlen(path_name))
+				free((char*) p);
+			if (path_name != buf.buf)
+				free(path_name);
+		}
+	}
+
+ finish:
+	if (active_cache_changed) {
+		if (write_cache(newfd, active_cache, active_nr) ||
+		    commit_lock_file(lock_file))
+			die("Unable to write new index file");
+	}
+
+	rollback_lock_file(lock_file);
+
+	return has_errors ? 1 : 0;
+}