merge(3p/git): Merge git subtree at v2.29.2 r/1890

This also bumps the stable nixpkgs to 20.09 as of 2020-11-21, because
there is some breakage in the git build related to the netrc
credentials helper which someone has taken care of in nixpkgs.

The stable channel is not used for anything other than git, so this
should be fine.

Change-Id: I3575a19dab09e1e9556cf8231d717de9890484fb

1 files changed, 184 insertions, 39 deletions

diff --git a/third_party/git/setup.c b/third_party/git/setup.c
index 8dcb4631f7d3..c04cd25a30df 100644
--- a/third_party/git/setup.c
+++ b/third_party/git/setup.c
@@ -4,6 +4,7 @@
 #include "dir.h"
 #include "string-list.h"
 #include "chdir-notify.h"
+#include "promisor-remote.h"
 
 static int inside_git_dir = -1;
 static int inside_work_tree = -1;
@@ -31,6 +32,7 @@ static int abspath_part_inside_repo(char *path)
 	char *path0;
 	int off;
 	const char *work_tree = get_git_work_tree();
+	struct strbuf realpath = STRBUF_INIT;
 
 	if (!work_tree)
 		return -1;
@@ -59,8 +61,10 @@ static int abspath_part_inside_repo(char *path)
 		path++;
 		if (*path == '/') {
 			*path = '\0';
-			if (fspathcmp(real_path(path0), work_tree) == 0) {
+			strbuf_realpath(&realpath, path0, 1);
+			if (fspathcmp(realpath.buf, work_tree) == 0) {
 				memmove(path0, path + 1, len - (path - path0));
+				strbuf_release(&realpath);
 				return 0;
 			}
 			*path = '/';
@@ -68,11 +72,14 @@ static int abspath_part_inside_repo(char *path)
 	}
 
 	/* check whole path */
-	if (fspathcmp(real_path(path0), work_tree) == 0) {
+	strbuf_realpath(&realpath, path0, 1);
+	if (fspathcmp(realpath.buf, work_tree) == 0) {
 		*path0 = '\0';
+		strbuf_release(&realpath);
 		return 0;
 	}
 
+	strbuf_release(&realpath);
 	return -1;
 }
 
@@ -119,8 +126,13 @@ char *prefix_path_gently(const char *prefix, int len,
 char *prefix_path(const char *prefix, int len, const char *path)
 {
 	char *r = prefix_path_gently(prefix, len, NULL, path);
-	if (!r)
-		die(_("'%s' is outside repository"), path);
+	if (!r) {
+		const char *hint_path = get_git_work_tree();
+		if (!hint_path)
+			hint_path = get_git_dir();
+		die(_("'%s' is outside repository at '%s'"), path,
+		    absolute_path(hint_path));
+	}
 	return r;
 }
 
@@ -196,9 +208,26 @@ static void NORETURN die_verify_filename(struct repository *r,
  */
 static int looks_like_pathspec(const char *arg)
 {
-	/* anything with a wildcard character */
-	if (!no_wildcard(arg))
-		return 1;
+	const char *p;
+	int escaped = 0;
+
+	/*
+	 * Wildcard characters imply the user is looking to match pathspecs
+	 * that aren't in the filesystem. Note that this doesn't include
+	 * backslash even though it's a glob special; by itself it doesn't
+	 * cause any increase in the match. Likewise ignore backslash-escaped
+	 * wildcard characters.
+	 */
+	for (p = arg; *p; p++) {
+		if (escaped) {
+			escaped = 0;
+		} else if (is_glob_special(*p)) {
+			if (*p == '\\')
+				escaped = 1;
+			else
+				return 1;
+		}
+	}
 
 	/* long-form pathspec magic */
 	if (starts_with(arg, ":("))
@@ -418,6 +447,63 @@ static int read_worktree_config(const char *var, const char *value, void *vdata)
 	return 0;
 }
 
+enum extension_result {
+	EXTENSION_ERROR = -1, /* compatible with error(), etc */
+	EXTENSION_UNKNOWN = 0,
+	EXTENSION_OK = 1
+};
+
+/*
+ * Do not add new extensions to this function. It handles extensions which are
+ * respected even in v0-format repositories for historical compatibility.
+ */
+static enum extension_result handle_extension_v0(const char *var,
+						 const char *value,
+						 const char *ext,
+						 struct repository_format *data)
+{
+		if (!strcmp(ext, "noop")) {
+			return EXTENSION_OK;
+		} else if (!strcmp(ext, "preciousobjects")) {
+			data->precious_objects = git_config_bool(var, value);
+			return EXTENSION_OK;
+		} else if (!strcmp(ext, "partialclone")) {
+			if (!value)
+				return config_error_nonbool(var);
+			data->partial_clone = xstrdup(value);
+			return EXTENSION_OK;
+		} else if (!strcmp(ext, "worktreeconfig")) {
+			data->worktree_config = git_config_bool(var, value);
+			return EXTENSION_OK;
+		}
+
+		return EXTENSION_UNKNOWN;
+}
+
+/*
+ * Record any new extensions in this function.
+ */
+static enum extension_result handle_extension(const char *var,
+					      const char *value,
+					      const char *ext,
+					      struct repository_format *data)
+{
+	if (!strcmp(ext, "noop-v1")) {
+		return EXTENSION_OK;
+	} else if (!strcmp(ext, "objectformat")) {
+		int format;
+
+		if (!value)
+			return config_error_nonbool(var);
+		format = hash_algo_by_name(value);
+		if (format == GIT_HASH_UNKNOWN)
+			return error("invalid value for 'extensions.objectformat'");
+		data->hash_algo = format;
+		return EXTENSION_OK;
+	}
+	return EXTENSION_UNKNOWN;
+}
+
 static int check_repo_format(const char *var, const char *value, void *vdata)
 {
 	struct repository_format *data = vdata;
@@ -426,23 +512,25 @@ static int check_repo_format(const char *var, const char *value, void *vdata)
 	if (strcmp(var, "core.repositoryformatversion") == 0)
 		data->version = git_config_int(var, value);
 	else if (skip_prefix(var, "extensions.", &ext)) {
-		/*
-		 * record any known extensions here; otherwise,
-		 * we fall through to recording it as unknown, and
-		 * check_repository_format will complain
-		 */
-		if (!strcmp(ext, "noop"))
-			;
-		else if (!strcmp(ext, "preciousobjects"))
-			data->precious_objects = git_config_bool(var, value);
-		else if (!strcmp(ext, "partialclone")) {
-			if (!value)
-				return config_error_nonbool(var);
-			data->partial_clone = xstrdup(value);
-		} else if (!strcmp(ext, "worktreeconfig"))
-			data->worktree_config = git_config_bool(var, value);
-		else
+		switch (handle_extension_v0(var, value, ext, data)) {
+		case EXTENSION_ERROR:
+			return -1;
+		case EXTENSION_OK:
+			return 0;
+		case EXTENSION_UNKNOWN:
+			break;
+		}
+
+		switch (handle_extension(var, value, ext, data)) {
+		case EXTENSION_ERROR:
+			return -1;
+		case EXTENSION_OK:
+			string_list_append(&data->v1_only_extensions, ext);
+			return 0;
+		case EXTENSION_UNKNOWN:
 			string_list_append(&data->unknown_extensions, ext);
+			return 0;
+		}
 	}
 
 	return read_worktree_config(var, value, vdata);
@@ -478,9 +566,10 @@ static int check_repository_format_gently(const char *gitdir, struct repository_
 	}
 
 	repository_format_precious_objects = candidate->precious_objects;
-	repository_format_partial_clone = xstrdup_or_null(candidate->partial_clone);
+	set_repository_format_partial_clone(candidate->partial_clone);
 	repository_format_worktree_config = candidate->worktree_config;
 	string_list_clear(&candidate->unknown_extensions, 0);
+	string_list_clear(&candidate->v1_only_extensions, 0);
 
 	if (repository_format_worktree_config) {
 		/*
@@ -509,6 +598,37 @@ static int check_repository_format_gently(const char *gitdir, struct repository_
 	return 0;
 }
 
+int upgrade_repository_format(int target_version)
+{
+	struct strbuf sb = STRBUF_INIT;
+	struct strbuf err = STRBUF_INIT;
+	struct strbuf repo_version = STRBUF_INIT;
+	struct repository_format repo_fmt = REPOSITORY_FORMAT_INIT;
+
+	strbuf_git_common_path(&sb, the_repository, "config");
+	read_repository_format(&repo_fmt, sb.buf);
+	strbuf_release(&sb);
+
+	if (repo_fmt.version >= target_version)
+		return 0;
+
+	if (verify_repository_format(&repo_fmt, &err) < 0) {
+		error("cannot upgrade repository format from %d to %d: %s",
+		      repo_fmt.version, target_version, err.buf);
+		strbuf_release(&err);
+		return -1;
+	}
+	if (!repo_fmt.version && repo_fmt.unknown_extensions.nr)
+		return error("cannot upgrade repository format: "
+			     "unknown extension %s",
+			     repo_fmt.unknown_extensions.items[0].string);
+
+	strbuf_addf(&repo_version, "%d", target_version);
+	git_config_set("core.repositoryformatversion", repo_version.buf);
+	strbuf_release(&repo_version);
+	return 1;
+}
+
 static void init_repository_format(struct repository_format *format)
 {
 	const struct repository_format fresh = REPOSITORY_FORMAT_INIT;
@@ -528,6 +648,7 @@ int read_repository_format(struct repository_format *format, const char *path)
 void clear_repository_format(struct repository_format *format)
 {
 	string_list_clear(&format->unknown_extensions, 0);
+	string_list_clear(&format->v1_only_extensions, 0);
 	free(format->work_tree);
 	free(format->partial_clone);
 	init_repository_format(format);
@@ -553,6 +674,18 @@ int verify_repository_format(const struct repository_format *format,
 		return -1;
 	}
 
+	if (format->version == 0 && format->v1_only_extensions.nr) {
+		int i;
+
+		strbuf_addstr(err,
+			      _("repo version is 0, but v1-only extensions found:"));
+
+		for (i = 0; i < format->v1_only_extensions.nr; i++)
+			strbuf_addf(err, "\n\t%s",
+				    format->v1_only_extensions.items[i].string);
+		return -1;
+	}
+
 	return 0;
 }
 
@@ -600,6 +733,7 @@ const char *read_gitfile_gently(const char *path, int *return_error_code)
 	struct stat st;
 	int fd;
 	ssize_t len;
+	static struct strbuf realpath = STRBUF_INIT;
 
 	if (stat(path, &st)) {
 		/* NEEDSWORK: discern between ENOENT vs other errors */
@@ -650,7 +784,9 @@ const char *read_gitfile_gently(const char *path, int *return_error_code)
 		error_code = READ_GITFILE_ERR_NOT_A_REPO;
 		goto cleanup_return;
 	}
-	path = real_path(dir);
+
+	strbuf_realpath(&realpath, dir, 1);
+	path = realpath.buf;
 
 cleanup_return:
 	if (return_error_code)
@@ -706,7 +842,7 @@ static const char *setup_explicit_git_dir(const char *gitdirenv,
 		}
 
 		/* #18, #26 */
-		set_git_dir(gitdirenv);
+		set_git_dir(gitdirenv, 0);
 		free(gitfile);
 		return NULL;
 	}
@@ -728,7 +864,7 @@ static const char *setup_explicit_git_dir(const char *gitdirenv,
 	}
 	else if (!git_env_bool(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, 1)) {
 		/* #16d */
-		set_git_dir(gitdirenv);
+		set_git_dir(gitdirenv, 0);
 		free(gitfile);
 		return NULL;
 	}
@@ -740,14 +876,14 @@ static const char *setup_explicit_git_dir(const char *gitdirenv,
 
 	/* both get_git_work_tree() and cwd are already normalized */
 	if (!strcmp(cwd->buf, worktree)) { /* cwd == worktree */
-		set_git_dir(gitdirenv);
+		set_git_dir(gitdirenv, 0);
 		free(gitfile);
 		return NULL;
 	}
 
 	offset = dir_inside_of(cwd->buf, worktree);
 	if (offset >= 0) {	/* cwd inside worktree? */
-		set_git_dir(real_path(gitdirenv));
+		set_git_dir(gitdirenv, 1);
 		if (chdir(worktree))
 			die_errno(_("cannot chdir to '%s'"), worktree);
 		strbuf_addch(cwd, '/');
@@ -756,7 +892,7 @@ static const char *setup_explicit_git_dir(const char *gitdirenv,
 	}
 
 	/* cwd outside worktree */
-	set_git_dir(gitdirenv);
+	set_git_dir(gitdirenv, 0);
 	free(gitfile);
 	return NULL;
 }
@@ -785,7 +921,7 @@ static const char *setup_discovered_git_dir(const char *gitdir,
 
 	/* #16.2, #17.2, #20.2, #21.2, #24, #25, #28, #29 (see t1510) */
 	if (is_bare_repository_cfg > 0) {
-		set_git_dir(offset == cwd->len ? gitdir : real_path(gitdir));
+		set_git_dir(gitdir, (offset != cwd->len));
 		if (chdir(cwd->buf))
 			die_errno(_("cannot come back to cwd"));
 		return NULL;
@@ -794,10 +930,10 @@ static const char *setup_discovered_git_dir(const char *gitdir,
 	/* #0, #1, #5, #8, #9, #12, #13 */
 	set_git_work_tree(".");
 	if (strcmp(gitdir, DEFAULT_GIT_DIR_ENVIRONMENT))
-		set_git_dir(gitdir);
+		set_git_dir(gitdir, 0);
 	inside_git_dir = 0;
 	inside_work_tree = 1;
-	if (offset == cwd->len)
+	if (offset >= cwd->len)
 		return NULL;
 
 	/* Make "offset" point past the '/' (already the case for root dirs) */
@@ -837,10 +973,10 @@ static const char *setup_bare_git_dir(struct strbuf *cwd, int offset,
 			die_errno(_("cannot come back to cwd"));
 		root_len = offset_1st_component(cwd->buf);
 		strbuf_setlen(cwd, offset > root_len ? offset : root_len);
-		set_git_dir(cwd->buf);
+		set_git_dir(cwd->buf, 0);
 	}
 	else
-		set_git_dir(".");
+		set_git_dir(".", 0);
 	return NULL;
 }
 
@@ -858,7 +994,7 @@ static dev_t get_device_or_die(const char *path, const char *prefix, int prefix_
 
 /*
  * A "string_list_each_func_t" function that canonicalizes an entry
- * from GIT_CEILING_DIRECTORIES using real_path_if_valid(), or
+ * from GIT_CEILING_DIRECTORIES using real_pathdup(), or
  * discards it if unusable.  The presence of an empty entry in
  * GIT_CEILING_DIRECTORIES turns off canonicalization for all
  * subsequent entries.
@@ -919,7 +1055,7 @@ static enum discovery_result setup_git_directory_gently_1(struct strbuf *dir,
 	const char *env_ceiling_dirs = getenv(CEILING_DIRECTORIES_ENVIRONMENT);
 	struct string_list ceiling_dirs = STRING_LIST_INIT_DUP;
 	const char *gitdirenv;
-	int ceil_offset = -1, min_offset = has_dos_drive_prefix(dir->buf) ? 3 : 1;
+	int ceil_offset = -1, min_offset = offset_1st_component(dir->buf);
 	dev_t current_device = 0;
 	int one_filesystem = 1;
 
@@ -947,6 +1083,12 @@ static enum discovery_result setup_git_directory_gently_1(struct strbuf *dir,
 	if (ceil_offset < 0)
 		ceil_offset = min_offset - 2;
 
+	if (min_offset && min_offset == dir->len &&
+	    !is_dir_sep(dir->buf[min_offset - 1])) {
+		strbuf_addch(dir, '/');
+		min_offset++;
+	}
+
 	/*
 	 * Test in the following order (relative to the dir):
 	 * - .git (file containing "gitdir: <path>")
@@ -1228,11 +1370,14 @@ int git_config_perm(const char *var, const char *value)
 	return -(i & 0666);
 }
 
-void check_repository_format(void)
+void check_repository_format(struct repository_format *fmt)
 {
 	struct repository_format repo_fmt = REPOSITORY_FORMAT_INIT;
-	check_repository_format_gently(get_git_dir(), &repo_fmt, NULL);
+	if (!fmt)
+		fmt = &repo_fmt;
+	check_repository_format_gently(get_git_dir(), fmt, NULL);
 	startup_info->have_repository = 1;
+	repo_set_hash_algo(the_repository, fmt->hash_algo);
 	clear_repository_format(&repo_fmt);
 }