1 files changed, 264 insertions, 103 deletions

diff --git a/builtin/apply.c b/builtin/apply.c
index bc924ab2d0..0ca687fa6b 100644
--- a/builtin/apply.c
+++ b/builtin/apply.c
@@ -7,6 +7,7 @@
  *
  */
 #include "cache.h"
+#include "lockfile.h"
 #include "cache-tree.h"
 #include "quote.h"
 #include "blob.h"
@@ -50,6 +51,7 @@ static int apply_verbosely;
 static int allow_overlap;
 static int no_add;
 static int threeway;
+static int unsafe_paths;
 static const char *fake_ancestor;
 static int line_termination = '\n';
 static unsigned int p_context = UINT_MAX;
@@ -435,7 +437,7 @@ static unsigned long linelen(const char *buffer, unsigned long size)
 
 static int is_dev_null(const char *str)
 {
-	return !memcmp("/dev/null", str, 9) && isspace(str[9]);
+	return skip_prefix(str, "/dev/null", &str) && isspace(*str);
 }
 
 #define TERM_SPACE	1
@@ -656,11 +658,6 @@ static size_t diff_timestamp_len(const char *line, size_t len)
 	return line + len - end;
 }
 
-static char *null_strdup(const char *s)
-{
-	return s ? xstrdup(s) : NULL;
-}
-
 static char *find_name_common(const char *line, const char *def,
 			      int p_value, const char *end, int terminate)
 {
@@ -683,10 +680,10 @@ static char *find_name_common(const char *line, const char *def,
 			start = line;
 	}
 	if (!start)
-		return squash_slash(null_strdup(def));
+		return squash_slash(xstrdup_or_null(def));
 	len = line - start;
 	if (!len)
-		return squash_slash(null_strdup(def));
+		return squash_slash(xstrdup_or_null(def));
 
 	/*
 	 * Generally we prefer the shorter name, especially
@@ -908,7 +905,7 @@ static void parse_traditional_patch(const char *first, const char *second, struc
 			patch->old_name = name;
 		} else {
 			patch->old_name = name;
-			patch->new_name = null_strdup(name);
+			patch->new_name = xstrdup_or_null(name);
 		}
 	}
 	if (!name)
@@ -997,7 +994,7 @@ static int gitdiff_delete(const char *line, struct patch *patch)
 {
 	patch->is_delete = 1;
 	free(patch->old_name);
-	patch->old_name = null_strdup(patch->def_name);
+	patch->old_name = xstrdup_or_null(patch->def_name);
 	return gitdiff_oldmode(line, patch);
 }
 
@@ -1005,7 +1002,7 @@ static int gitdiff_newfile(const char *line, struct patch *patch)
 {
 	patch->is_new = 1;
 	free(patch->new_name);
-	patch->new_name = null_strdup(patch->def_name);
+	patch->new_name = xstrdup_or_null(patch->def_name);
 	return gitdiff_newmode(line, patch);
 }
 
@@ -1075,7 +1072,7 @@ static int gitdiff_index(const char *line, struct patch *patch)
 
 	line = ptr + 2;
 	ptr = strchr(line, ' ');
-	eol = strchr(line, '\n');
+	eol = strchrnul(line, '\n');
 
 	if (!ptr || eol < ptr)
 		ptr = eol;
@@ -1281,9 +1278,7 @@ static int parse_git_header(const char *line, int len, unsigned int size, struct
 	 */
 	patch->def_name = git_header_name(line, len);
 	if (patch->def_name && root) {
-		char *s = xmalloc(root_len + strlen(patch->def_name) + 1);
-		strcpy(s, root);
-		strcpy(s + root_len, patch->def_name);
+		char *s = xstrfmt("%s%s", root, patch->def_name);
 		free(patch->def_name);
 		patch->def_name = s;
 	}
@@ -1922,6 +1917,66 @@ static int parse_binary(char *buffer, unsigned long size, struct patch *patch)
 	return used;
 }
 
+static void prefix_one(char **name)
+{
+	char *old_name = *name;
+	if (!old_name)
+		return;
+	*name = xstrdup(prefix_filename(prefix, prefix_length, *name));
+	free(old_name);
+}
+
+static void prefix_patch(struct patch *p)
+{
+	if (!prefix || p->is_toplevel_relative)
+		return;
+	prefix_one(&p->new_name);
+	prefix_one(&p->old_name);
+}
+
+/*
+ * include/exclude
+ */
+
+static struct string_list limit_by_name;
+static int has_include;
+static void add_name_limit(const char *name, int exclude)
+{
+	struct string_list_item *it;
+
+	it = string_list_append(&limit_by_name, name);
+	it->util = exclude ? NULL : (void *) 1;
+}
+
+static int use_patch(struct patch *p)
+{
+	const char *pathname = p->new_name ? p->new_name : p->old_name;
+	int i;
+
+	/* Paths outside are not touched regardless of "--include" */
+	if (0 < prefix_length) {
+		int pathlen = strlen(pathname);
+		if (pathlen <= prefix_length ||
+		    memcmp(prefix, pathname, prefix_length))
+			return 0;
+	}
+
+	/* See if it matches any of exclude/include rule */
+	for (i = 0; i < limit_by_name.nr; i++) {
+		struct string_list_item *it = &limit_by_name.items[i];
+		if (!wildmatch(it->string, pathname, 0, NULL))
+			return (it->util != NULL);
+	}
+
+	/*
+	 * If we had any include, a path that does not match any rule is
+	 * not used.  Otherwise, we saw bunch of exclude rules (or none)
+	 * and such a path is used.
+	 */
+	return !has_include;
+}
+
+
 /*
  * Read the patch text in "buffer" that extends for "size" bytes; stop
  * reading after seeing a single patch (i.e. changes to a single file).
@@ -1937,9 +1992,14 @@ static int parse_chunk(char *buffer, unsigned long size, struct patch *patch)
 	if (offset < 0)
 		return offset;
 
-	patch->ws_rule = whitespace_rule(patch->new_name
-					 ? patch->new_name
-					 : patch->old_name);
+	prefix_patch(patch);
+
+	if (!use_patch(patch))
+		patch->ws_rule = 0;
+	else
+		patch->ws_rule = whitespace_rule(patch->new_name
+						 ? patch->new_name
+						 : patch->old_name);
 
 	patchsize = parse_single_patch(buffer + offset + hdrsize,
 				       size - offset - hdrsize, patch);
@@ -2171,6 +2231,12 @@ static void update_pre_post_images(struct image *preimage,
 		ctx++;
 	}
 
+	if (postlen
+	    ? postlen < new - postimage->buf
+	    : postimage->len < new - postimage->buf)
+		die("BUG: caller miscounted postlen: asked %d, orig = %d, used = %d",
+		    (int)postlen, (int) postimage->len, (int)(new - postimage->buf));
+
 	/* Fix the length of the whole thing */
 	postimage->len = new - postimage->buf;
 	postimage->nr -= reduced;
@@ -2326,10 +2392,27 @@ static int match_fragment(struct image *img,
 
 	/*
 	 * The hunk does not apply byte-by-byte, but the hash says
-	 * it might with whitespace fuzz. We haven't been asked to
+	 * it might with whitespace fuzz. We weren't asked to
 	 * ignore whitespace, we were asked to correct whitespace
 	 * errors, so let's try matching after whitespace correction.
 	 *
+	 * While checking the preimage against the target, whitespace
+	 * errors in both fixed, we count how large the corresponding
+	 * postimage needs to be.  The postimage prepared by
+	 * apply_one_fragment() has whitespace errors fixed on added
+	 * lines already, but the common lines were propagated as-is,
+	 * which may become longer when their whitespace errors are
+	 * fixed.
+	 */
+
+	/* First count added lines in postimage */
+	postlen = 0;
+	for (i = 0; i < postimage->nr; i++) {
+		if (!(postimage->line[i].flag & LINE_COMMON))
+			postlen += postimage->line[i].len;
+	}
+
+	/*
 	 * The preimage may extend beyond the end of the file,
 	 * but in this loop we will only handle the part of the
 	 * preimage that falls within the file.
@@ -2337,7 +2420,6 @@ static int match_fragment(struct image *img,
 	strbuf_init(&fixed, preimage->len + 1);
 	orig = preimage->buf;
 	target = img->buf + try;
-	postlen = 0;
 	for (i = 0; i < preimage_limit; i++) {
 		size_t oldlen = preimage->line[i].len;
 		size_t tgtlen = img->line[try_lno + i].len;
@@ -2365,7 +2447,10 @@ static int match_fragment(struct image *img,
 		match = (tgtfix.len == fixed.len - fixstart &&
 			 !memcmp(tgtfix.buf, fixed.buf + fixstart,
 					     fixed.len - fixstart));
-		postlen += tgtfix.len;
+
+		/* Add the length if this is common with the postimage */
+		if (preimage->line[i].flag & LINE_COMMON)
+			postlen += tgtfix.len;
 
 		strbuf_release(&tgtfix);
 		if (!match)
@@ -2563,7 +2648,7 @@ static void update_image(struct image *img,
 		 * NOTE: this knows that we never call remove_first_line()
 		 * on anything other than pre/post image.
 		 */
-		img->line = xrealloc(img->line, nr * sizeof(*img->line));
+		REALLOC_ARRAY(img->line, nr);
 		img->line_allocated = img->line;
 	}
 	if (preimage_limit != postimage->nr)
@@ -2869,9 +2954,7 @@ static int apply_binary_fragment(struct image *img, struct patch *patch)
 	case BINARY_LITERAL_DEFLATED:
 		clear_image(img);
 		img->len = fragment->size;
-		img->buf = xmalloc(img->len+1);
-		memcpy(img->buf, fragment->patch, img->len);
-		img->buf[img->len] = '\0';
+		img->buf = xmemdupz(fragment->patch, img->len);
 		return 0;
 	}
 	return -1;
@@ -3086,13 +3169,15 @@ static void prepare_fn_table(struct patch *patch)
 	}
 }
 
-static int checkout_target(struct cache_entry *ce, struct stat *st)
+static int checkout_target(struct index_state *istate,
+			   struct cache_entry *ce, struct stat *st)
 {
 	struct checkout costate;
 
 	memset(&costate, 0, sizeof(costate));
 	costate.base_dir = "";
 	costate.refresh_cache = 1;
+	costate.istate = istate;
 	if (checkout_entry(ce, &costate, NULL) || lstat(ce->name, st))
 		return error(_("cannot checkout %s"), ce->name);
 	return 0;
@@ -3137,7 +3222,7 @@ static int load_patch_target(struct strbuf *buf,
 			     const char *name,
 			     unsigned expected_mode)
 {
-	if (cached) {
+	if (cached || check_index) {
 		if (read_file_or_gitlink(ce, buf))
 			return error(_("read of %s failed"), name);
 	} else if (name) {
@@ -3146,6 +3231,8 @@ static int load_patch_target(struct strbuf *buf,
 				return read_file_or_gitlink(ce, buf);
 			else
 				return SUBMODULE_PATCH_WITHOUT_INDEX;
+		} else if (has_symlink_leading_path(name, strlen(name))) {
+			return error(_("reading from '%s' beyond a symbolic link"), name);
 		} else {
 			if (read_old_data(st, name, buf))
 				return error(_("read of %s failed"), name);
@@ -3259,7 +3346,7 @@ static int load_current(struct image *image, struct patch *patch)
 	if (lstat(name, &st)) {
 		if (errno != ENOENT)
 			return error(_("%s: %s"), name, strerror(errno));
-		if (checkout_target(ce, &st))
+		if (checkout_target(&the_index, ce, &st))
 			return -1;
 	}
 	if (verify_index_match(ce, &st))
@@ -3413,7 +3500,7 @@ static int check_preimage(struct patch *patch, struct cache_entry **ce, struct s
 		}
 		*ce = active_cache[pos];
 		if (stat_ret < 0) {
-			if (checkout_target(*ce, st))
+			if (checkout_target(&the_index, *ce, st))
 				return -1;
 		}
 		if (!cached && verify_index_match(*ce, st))
@@ -3486,6 +3573,121 @@ static int check_to_create(const char *new_name, int ok_if_exists)
 }
 
 /*
+ * We need to keep track of how symlinks in the preimage are
+ * manipulated by the patches.  A patch to add a/b/c where a/b
+ * is a symlink should not be allowed to affect the directory
+ * the symlink points at, but if the same patch removes a/b,
+ * it is perfectly fine, as the patch removes a/b to make room
+ * to create a directory a/b so that a/b/c can be created.
+ */
+static struct string_list symlink_changes;
+#define SYMLINK_GOES_AWAY 01
+#define SYMLINK_IN_RESULT 02
+
+static uintptr_t register_symlink_changes(const char *path, uintptr_t what)
+{
+	struct string_list_item *ent;
+
+	ent = string_list_lookup(&symlink_changes, path);
+	if (!ent) {
+		ent = string_list_insert(&symlink_changes, path);
+		ent->util = (void *)0;
+	}
+	ent->util = (void *)(what | ((uintptr_t)ent->util));
+	return (uintptr_t)ent->util;
+}
+
+static uintptr_t check_symlink_changes(const char *path)
+{
+	struct string_list_item *ent;
+
+	ent = string_list_lookup(&symlink_changes, path);
+	if (!ent)
+		return 0;
+	return (uintptr_t)ent->util;
+}
+
+static void prepare_symlink_changes(struct patch *patch)
+{
+	for ( ; patch; patch = patch->next) {
+		if ((patch->old_name && S_ISLNK(patch->old_mode)) &&
+		    (patch->is_rename || patch->is_delete))
+			/* the symlink at patch->old_name is removed */
+			register_symlink_changes(patch->old_name, SYMLINK_GOES_AWAY);
+
+		if (patch->new_name && S_ISLNK(patch->new_mode))
+			/* the symlink at patch->new_name is created or remains */
+			register_symlink_changes(patch->new_name, SYMLINK_IN_RESULT);
+	}
+}
+
+static int path_is_beyond_symlink_1(struct strbuf *name)
+{
+	do {
+		unsigned int change;
+
+		while (--name->len && name->buf[name->len] != '/')
+			; /* scan backwards */
+		if (!name->len)
+			break;
+		name->buf[name->len] = '\0';
+		change = check_symlink_changes(name->buf);
+		if (change & SYMLINK_IN_RESULT)
+			return 1;
+		if (change & SYMLINK_GOES_AWAY)
+			/*
+			 * This cannot be "return 0", because we may
+			 * see a new one created at a higher level.
+			 */
+			continue;
+
+		/* otherwise, check the preimage */
+		if (check_index) {
+			struct cache_entry *ce;
+
+			ce = cache_file_exists(name->buf, name->len, ignore_case);
+			if (ce && S_ISLNK(ce->ce_mode))
+				return 1;
+		} else {
+			struct stat st;
+			if (!lstat(name->buf, &st) && S_ISLNK(st.st_mode))
+				return 1;
+		}
+	} while (1);
+	return 0;
+}
+
+static int path_is_beyond_symlink(const char *name_)
+{
+	int ret;
+	struct strbuf name = STRBUF_INIT;
+
+	assert(*name_ != '\0');
+	strbuf_addstr(&name, name_);
+	ret = path_is_beyond_symlink_1(&name);
+	strbuf_release(&name);
+
+	return ret;
+}
+
+static void die_on_unsafe_path(struct patch *patch)
+{
+	const char *old_name = NULL;
+	const char *new_name = NULL;
+	if (patch->is_delete)
+		old_name = patch->old_name;
+	else if (!patch->is_new && !patch->is_copy)
+		old_name = patch->old_name;
+	if (!patch->is_delete)
+		new_name = patch->new_name;
+
+	if (old_name && !verify_path(old_name))
+		die(_("invalid path '%s'"), old_name);
+	if (new_name && !verify_path(new_name))
+		die(_("invalid path '%s'"), new_name);
+}
+
+/*
  * Check and apply the patch in-core; leave the result in patch->result
  * for the caller to write it out to the final destination.
  */
@@ -3572,6 +3774,22 @@ static int check_patch(struct patch *patch)
 		}
 	}
 
+	if (!unsafe_paths)
+		die_on_unsafe_path(patch);
+
+	/*
+	 * An attempt to read from or delete a path that is beyond a
+	 * symbolic link will be prevented by load_patch_target() that
+	 * is called at the beginning of apply_data() so we do not
+	 * have to worry about a patch marked with "is_delete" bit
+	 * here.  We however need to make sure that the patch result
+	 * is not deposited to a path that is beyond a symbolic link
+	 * here.
+	 */
+	if (!patch->is_delete && path_is_beyond_symlink(patch->new_name))
+		return error(_("affected file '%s' is beyond a symbolic link"),
+			     patch->new_name);
+
 	if (apply_data(patch, &st, ce) < 0)
 		return error(_("%s: patch does not apply"), name);
 	patch->rejected = 0;
@@ -3582,6 +3800,7 @@ static int check_patch_list(struct patch *patch)
 {
 	int err = 0;
 
+	prepare_symlink_changes(patch);
 	prepare_fn_table(patch);
 	while (patch) {
 		if (apply_verbosely)
@@ -3646,7 +3865,7 @@ static void build_fake_ancestor(struct patch *list, const char *filename)
 {
 	struct patch *patch;
 	struct index_state result = { NULL };
-	int fd;
+	static struct lock_file lock;
 
 	/* Once we start supporting the reverse patch, it may be
 	 * worth showing the new sha1 prefix, but until then...
@@ -3664,7 +3883,7 @@ static void build_fake_ancestor(struct patch *list, const char *filename)
 			if (!preimage_sha1_in_gitlink_patch(patch, sha1))
 				; /* ok, the textual part looks sane */
 			else
-				die("sha1 information is lacking or useless for submoule %s",
+				die("sha1 information is lacking or useless for submodule %s",
 				    name);
 		} else if (!get_sha1_blob(patch->old_sha1_prefix, sha1)) {
 			; /* ok */
@@ -3684,8 +3903,8 @@ static void build_fake_ancestor(struct patch *list, const char *filename)
 			die ("Could not add %s to temporary index", name);
 	}
 
-	fd = open(filename, O_WRONLY | O_CREAT, 0666);
-	if (fd < 0 || write_index(&result, fd) || close(fd))
+	hold_lock_file_for_update(&lock, filename, LOCK_DIE_ON_ERROR);
+	if (write_locked_index(&result, &lock, COMMIT_LOCK))
 		die ("Could not write temporary index to %s", filename);
 
 	discard_index(&result);
@@ -4116,7 +4335,7 @@ static int write_out_results(struct patch *list)
 	if (cpath.nr) {
 		struct string_list_item *item;
 
-		sort_string_list(&cpath);
+		string_list_sort(&cpath);
 		for_each_string_list_item(item, &cpath)
 			fprintf(stderr, "U %s\n", item->string);
 		string_list_clear(&cpath, 0);
@@ -4129,64 +4348,6 @@ static int write_out_results(struct patch *list)
 
 static struct lock_file lock_file;
 
-static struct string_list limit_by_name;
-static int has_include;
-static void add_name_limit(const char *name, int exclude)
-{
-	struct string_list_item *it;
-
-	it = string_list_append(&limit_by_name, name);
-	it->util = exclude ? NULL : (void *) 1;
-}
-
-static int use_patch(struct patch *p)
-{
-	const char *pathname = p->new_name ? p->new_name : p->old_name;
-	int i;
-
-	/* Paths outside are not touched regardless of "--include" */
-	if (0 < prefix_length) {
-		int pathlen = strlen(pathname);
-		if (pathlen <= prefix_length ||
-		    memcmp(prefix, pathname, prefix_length))
-			return 0;
-	}
-
-	/* See if it matches any of exclude/include rule */
-	for (i = 0; i < limit_by_name.nr; i++) {
-		struct string_list_item *it = &limit_by_name.items[i];
-		if (!wildmatch(it->string, pathname, 0, NULL))
-			return (it->util != NULL);
-	}
-
-	/*
-	 * If we had any include, a path that does not match any rule is
-	 * not used.  Otherwise, we saw bunch of exclude rules (or none)
-	 * and such a path is used.
-	 */
-	return !has_include;
-}
-
-
-static void prefix_one(char **name)
-{
-	char *old_name = *name;
-	if (!old_name)
-		return;
-	*name = xstrdup(prefix_filename(prefix, prefix_length, *name));
-	free(old_name);
-}
-
-static void prefix_patches(struct patch *p)
-{
-	if (!prefix || p->is_toplevel_relative)
-		return;
-	for ( ; p; p = p->next) {
-		prefix_one(&p->new_name);
-		prefix_one(&p->old_name);
-	}
-}
-
 #define INACCURATE_EOF	(1<<0)
 #define RECOUNT		(1<<1)
 
@@ -4212,8 +4373,6 @@ static int apply_patch(int fd, const char *filename, int options)
 			break;
 		if (apply_in_reverse)
 			reverse_patches(patch);
-		if (prefix)
-			prefix_patches(patch);
 		if (use_patch(patch)) {
 			patch_stats(patch);
 			*listp = patch;
@@ -4271,13 +4430,11 @@ static int apply_patch(int fd, const char *filename, int options)
 	return 0;
 }
 
-static int git_apply_config(const char *var, const char *value, void *cb)
+static void git_apply_config(void)
 {
-	if (!strcmp(var, "apply.whitespace"))
-		return git_config_string(&apply_default_whitespace, var, value);
-	else if (!strcmp(var, "apply.ignorewhitespace"))
-		return git_config_string(&apply_default_ignorewhitespace, var, value);
-	return git_default_config(var, value, cb);
+	git_config_get_string_const("apply.whitespace", &apply_default_whitespace);
+	git_config_get_string_const("apply.ignorewhitespace", &apply_default_ignorewhitespace);
+	git_config(git_default_config, NULL);
 }
 
 static int option_parse_exclude(const struct option *opt,
@@ -4382,6 +4539,8 @@ int cmd_apply(int argc, const char **argv, const char *prefix_)
 			N_("make sure the patch is applicable to the current index")),
 		OPT_BOOL(0, "cached", &cached,
 			N_("apply a patch without touching the working tree")),
+		OPT_BOOL(0, "unsafe-paths", &unsafe_paths,
+			N_("accept a patch that touches outside the working area")),
 		OPT_BOOL(0, "apply", &force_apply,
 			N_("also apply the patch (use with --stat/--summary/--check)")),
 		OPT_BOOL('3', "3way", &threeway,
@@ -4425,7 +4584,7 @@ int cmd_apply(int argc, const char **argv, const char *prefix_)
 
 	prefix = prefix_;
 	prefix_length = prefix ? strlen(prefix) : 0;
-	git_config(git_apply_config, NULL);
+	git_apply_config();
 	if (apply_default_whitespace)
 		parse_whitespace_option(apply_default_whitespace);
 	if (apply_default_ignorewhitespace)
@@ -4454,6 +4613,9 @@ int cmd_apply(int argc, const char **argv, const char *prefix_)
 			die(_("--cached outside a repository"));
 		check_index = 1;
 	}
+	if (check_index)
+		unsafe_paths = 0;
+
 	for (i = 0; i < argc; i++) {
 		const char *arg = argv[i];
 		int fd;
@@ -4504,8 +4666,7 @@ int cmd_apply(int argc, const char **argv, const char *prefix_)
 	}
 
 	if (update_index) {
-		if (write_cache(newfd, active_cache, active_nr) ||
-		    commit_locked_index(&lock_file))
+		if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
 			die(_("Unable to write new index file"));
 	}