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, 287 insertions, 71 deletions

diff --git a/third_party/git/list-objects-filter-options.c b/third_party/git/list-objects-filter-options.c
index 1cb20c659c..defd3dfd10 100644
--- a/third_party/git/list-objects-filter-options.c
+++ b/third_party/git/list-objects-filter-options.c
@@ -2,10 +2,41 @@
 #include "commit.h"
 #include "config.h"
 #include "revision.h"
-#include "argv-array.h"
+#include "strvec.h"
 #include "list-objects.h"
 #include "list-objects-filter.h"
 #include "list-objects-filter-options.h"
+#include "promisor-remote.h"
+#include "trace.h"
+#include "url.h"
+
+static int parse_combine_filter(
+	struct list_objects_filter_options *filter_options,
+	const char *arg,
+	struct strbuf *errbuf);
+
+const char *list_object_filter_config_name(enum list_objects_filter_choice c)
+{
+	switch (c) {
+	case LOFC_DISABLED:
+		/* we have no name for "no filter at all" */
+		break;
+	case LOFC_BLOB_NONE:
+		return "blob:none";
+	case LOFC_BLOB_LIMIT:
+		return "blob:limit";
+	case LOFC_TREE_DEPTH:
+		return "tree";
+	case LOFC_SPARSE_OID:
+		return "sparse:oid";
+	case LOFC_COMBINE:
+		return "combine";
+	case LOFC__COUNT:
+		/* not a real filter type; just the count of all filters */
+		break;
+	}
+	BUG("list_object_filter_choice_name: invalid argument '%d'", c);
+}
 
 /*
  * Parse value of the argument to the "filter" keyword.
@@ -29,16 +60,11 @@ static int gently_parse_list_objects_filter(
 {
 	const char *v0;
 
-	if (filter_options->choice) {
-		if (errbuf) {
-			strbuf_addstr(
-				errbuf,
-				_("multiple filter-specs cannot be combined"));
-		}
-		return 1;
-	}
+	if (!arg)
+		return 0;
 
-	filter_options->filter_spec = strdup(arg);
+	if (filter_options->choice)
+		BUG("filter_options already populated");
 
 	if (!strcmp(arg, "blob:none")) {
 		filter_options->choice = LOFC_BLOB_NONE;
@@ -52,28 +78,14 @@ static int gently_parse_list_objects_filter(
 
 	} else if (skip_prefix(arg, "tree:", &v0)) {
 		if (!git_parse_ulong(v0, &filter_options->tree_exclude_depth)) {
-			if (errbuf) {
-				strbuf_addstr(
-					errbuf,
-					_("expected 'tree:<depth>'"));
-			}
+			strbuf_addstr(errbuf, _("expected 'tree:<depth>'"));
 			return 1;
 		}
 		filter_options->choice = LOFC_TREE_DEPTH;
 		return 0;
 
 	} else if (skip_prefix(arg, "sparse:oid=", &v0)) {
-		struct object_context oc;
-		struct object_id sparse_oid;
-
-		/*
-		 * Try to parse <oid-expression> into an OID for the current
-		 * command, but DO NOT complain if we don't have the blob or
-		 * ref locally.
-		 */
-		if (!get_oid_with_context(the_repository, v0, GET_OID_BLOB,
-					  &sparse_oid, &oc))
-			filter_options->sparse_oid_value = oiddup(&sparse_oid);
+		filter_options->sparse_oid_name = xstrdup(v0);
 		filter_options->choice = LOFC_SPARSE_OID;
 		return 0;
 
@@ -84,103 +96,307 @@ static int gently_parse_list_objects_filter(
 				_("sparse:path filters support has been dropped"));
 		}
 		return 1;
+
+	} else if (skip_prefix(arg, "combine:", &v0)) {
+		return parse_combine_filter(filter_options, v0, errbuf);
+
 	}
 	/*
 	 * Please update _git_fetch() in git-completion.bash when you
 	 * add new filters
 	 */
 
-	if (errbuf)
-		strbuf_addf(errbuf, _("invalid filter-spec '%s'"), arg);
+	strbuf_addf(errbuf, _("invalid filter-spec '%s'"), arg);
 
 	memset(filter_options, 0, sizeof(*filter_options));
 	return 1;
 }
 
-int parse_list_objects_filter(struct list_objects_filter_options *filter_options,
-			      const char *arg)
+static const char *RESERVED_NON_WS = "~`!@#$^&*()[]{}\\;'\",<>?";
+
+static int has_reserved_character(
+	struct strbuf *sub_spec, struct strbuf *errbuf)
 {
-	struct strbuf buf = STRBUF_INIT;
-	if (gently_parse_list_objects_filter(filter_options, arg, &buf))
-		die("%s", buf.buf);
+	const char *c = sub_spec->buf;
+	while (*c) {
+		if (*c <= ' ' || strchr(RESERVED_NON_WS, *c)) {
+			strbuf_addf(
+				errbuf,
+				_("must escape char in sub-filter-spec: '%c'"),
+				*c);
+			return 1;
+		}
+		c++;
+	}
+
 	return 0;
 }
 
+static int parse_combine_subfilter(
+	struct list_objects_filter_options *filter_options,
+	struct strbuf *subspec,
+	struct strbuf *errbuf)
+{
+	size_t new_index = filter_options->sub_nr;
+	char *decoded;
+	int result;
+
+	ALLOC_GROW_BY(filter_options->sub, filter_options->sub_nr, 1,
+		      filter_options->sub_alloc);
+
+	decoded = url_percent_decode(subspec->buf);
+
+	result = has_reserved_character(subspec, errbuf) ||
+		gently_parse_list_objects_filter(
+			&filter_options->sub[new_index], decoded, errbuf);
+
+	free(decoded);
+	return result;
+}
+
+static int parse_combine_filter(
+	struct list_objects_filter_options *filter_options,
+	const char *arg,
+	struct strbuf *errbuf)
+{
+	struct strbuf **subspecs = strbuf_split_str(arg, '+', 0);
+	size_t sub;
+	int result = 0;
+
+	if (!subspecs[0]) {
+		strbuf_addstr(errbuf, _("expected something after combine:"));
+		result = 1;
+		goto cleanup;
+	}
+
+	for (sub = 0; subspecs[sub] && !result; sub++) {
+		if (subspecs[sub + 1]) {
+			/*
+			 * This is not the last subspec. Remove trailing "+" so
+			 * we can parse it.
+			 */
+			size_t last = subspecs[sub]->len - 1;
+			assert(subspecs[sub]->buf[last] == '+');
+			strbuf_remove(subspecs[sub], last, 1);
+		}
+		result = parse_combine_subfilter(
+			filter_options, subspecs[sub], errbuf);
+	}
+
+	filter_options->choice = LOFC_COMBINE;
+
+cleanup:
+	strbuf_list_free(subspecs);
+	if (result) {
+		list_objects_filter_release(filter_options);
+		memset(filter_options, 0, sizeof(*filter_options));
+	}
+	return result;
+}
+
+static int allow_unencoded(char ch)
+{
+	if (ch <= ' ' || ch == '%' || ch == '+')
+		return 0;
+	return !strchr(RESERVED_NON_WS, ch);
+}
+
+static void filter_spec_append_urlencode(
+	struct list_objects_filter_options *filter, const char *raw)
+{
+	struct strbuf buf = STRBUF_INIT;
+	strbuf_addstr_urlencode(&buf, raw, allow_unencoded);
+	trace_printf("Add to combine filter-spec: %s\n", buf.buf);
+	string_list_append(&filter->filter_spec, strbuf_detach(&buf, NULL));
+}
+
+/*
+ * Changes filter_options into an equivalent LOFC_COMBINE filter options
+ * instance. Does not do anything if filter_options is already LOFC_COMBINE.
+ */
+static void transform_to_combine_type(
+	struct list_objects_filter_options *filter_options)
+{
+	assert(filter_options->choice);
+	if (filter_options->choice == LOFC_COMBINE)
+		return;
+	{
+		const int initial_sub_alloc = 2;
+		struct list_objects_filter_options *sub_array =
+			xcalloc(initial_sub_alloc, sizeof(*sub_array));
+		sub_array[0] = *filter_options;
+		memset(filter_options, 0, sizeof(*filter_options));
+		filter_options->sub = sub_array;
+		filter_options->sub_alloc = initial_sub_alloc;
+	}
+	filter_options->sub_nr = 1;
+	filter_options->choice = LOFC_COMBINE;
+	string_list_append(&filter_options->filter_spec, xstrdup("combine:"));
+	filter_spec_append_urlencode(
+		filter_options,
+		list_objects_filter_spec(&filter_options->sub[0]));
+	/*
+	 * We don't need the filter_spec strings for subfilter specs, only the
+	 * top level.
+	 */
+	string_list_clear(&filter_options->sub[0].filter_spec, /*free_util=*/0);
+}
+
+void list_objects_filter_die_if_populated(
+	struct list_objects_filter_options *filter_options)
+{
+	if (filter_options->choice)
+		die(_("multiple filter-specs cannot be combined"));
+}
+
+void parse_list_objects_filter(
+	struct list_objects_filter_options *filter_options,
+	const char *arg)
+{
+	struct strbuf errbuf = STRBUF_INIT;
+	int parse_error;
+
+	if (!filter_options->choice) {
+		string_list_append(&filter_options->filter_spec, xstrdup(arg));
+
+		parse_error = gently_parse_list_objects_filter(
+			filter_options, arg, &errbuf);
+	} else {
+		/*
+		 * Make filter_options an LOFC_COMBINE spec so we can trivially
+		 * add subspecs to it.
+		 */
+		transform_to_combine_type(filter_options);
+
+		string_list_append(&filter_options->filter_spec, xstrdup("+"));
+		filter_spec_append_urlencode(filter_options, arg);
+		ALLOC_GROW_BY(filter_options->sub, filter_options->sub_nr, 1,
+			      filter_options->sub_alloc);
+
+		parse_error = gently_parse_list_objects_filter(
+			&filter_options->sub[filter_options->sub_nr - 1], arg,
+			&errbuf);
+	}
+	if (parse_error)
+		die("%s", errbuf.buf);
+}
+
 int opt_parse_list_objects_filter(const struct option *opt,
 				  const char *arg, int unset)
 {
 	struct list_objects_filter_options *filter_options = opt->value;
 
-	if (unset || !arg) {
+	if (unset || !arg)
 		list_objects_filter_set_no_filter(filter_options);
-		return 0;
+	else
+		parse_list_objects_filter(filter_options, arg);
+	return 0;
+}
+
+const char *list_objects_filter_spec(struct list_objects_filter_options *filter)
+{
+	if (!filter->filter_spec.nr)
+		BUG("no filter_spec available for this filter");
+	if (filter->filter_spec.nr != 1) {
+		struct strbuf concatted = STRBUF_INIT;
+		strbuf_add_separated_string_list(
+			&concatted, "", &filter->filter_spec);
+		string_list_clear(&filter->filter_spec, /*free_util=*/0);
+		string_list_append(
+			&filter->filter_spec, strbuf_detach(&concatted, NULL));
 	}
 
-	return parse_list_objects_filter(filter_options, arg);
+	return filter->filter_spec.items[0].string;
 }
 
-void expand_list_objects_filter_spec(
-	const struct list_objects_filter_options *filter,
-	struct strbuf *expanded_spec)
+const char *expand_list_objects_filter_spec(
+	struct list_objects_filter_options *filter)
 {
-	strbuf_init(expanded_spec, strlen(filter->filter_spec));
-	if (filter->choice == LOFC_BLOB_LIMIT)
-		strbuf_addf(expanded_spec, "blob:limit=%lu",
+	if (filter->choice == LOFC_BLOB_LIMIT) {
+		struct strbuf expanded_spec = STRBUF_INIT;
+		strbuf_addf(&expanded_spec, "blob:limit=%lu",
 			    filter->blob_limit_value);
-	else if (filter->choice == LOFC_TREE_DEPTH)
-		strbuf_addf(expanded_spec, "tree:%lu",
-			    filter->tree_exclude_depth);
-	else
-		strbuf_addstr(expanded_spec, filter->filter_spec);
+		string_list_clear(&filter->filter_spec, /*free_util=*/0);
+		string_list_append(
+			&filter->filter_spec,
+			strbuf_detach(&expanded_spec, NULL));
+	}
+
+	return list_objects_filter_spec(filter);
 }
 
 void list_objects_filter_release(
 	struct list_objects_filter_options *filter_options)
 {
-	free(filter_options->filter_spec);
-	free(filter_options->sparse_oid_value);
+	size_t sub;
+
+	if (!filter_options)
+		return;
+	string_list_clear(&filter_options->filter_spec, /*free_util=*/0);
+	free(filter_options->sparse_oid_name);
+	for (sub = 0; sub < filter_options->sub_nr; sub++)
+		list_objects_filter_release(&filter_options->sub[sub]);
+	free(filter_options->sub);
 	memset(filter_options, 0, sizeof(*filter_options));
 }
 
 void partial_clone_register(
 	const char *remote,
-	const struct list_objects_filter_options *filter_options)
+	struct list_objects_filter_options *filter_options)
 {
-	/*
-	 * Record the name of the partial clone remote in the
-	 * config and in the global variable -- the latter is
-	 * used throughout to indicate that partial clone is
-	 * enabled and to expect missing objects.
-	 */
-	if (repository_format_partial_clone &&
-	    *repository_format_partial_clone &&
-	    strcmp(remote, repository_format_partial_clone))
-		die(_("cannot change partial clone promisor remote"));
+	struct promisor_remote *promisor_remote;
+	char *cfg_name;
+	char *filter_name;
 
-	git_config_set("core.repositoryformatversion", "1");
-	git_config_set("extensions.partialclone", remote);
+	/* Check if it is already registered */
+	if ((promisor_remote = promisor_remote_find(remote))) {
+		if (promisor_remote->partial_clone_filter)
+			/*
+			 * Remote is already registered and a filter is already
+			 * set, so we don't need to do anything here.
+			 */
+			return;
+	} else {
+		if (upgrade_repository_format(1) < 0)
+			die(_("unable to upgrade repository format to support partial clone"));
 
-	repository_format_partial_clone = xstrdup(remote);
+		/* Add promisor config for the remote */
+		cfg_name = xstrfmt("remote.%s.promisor", remote);
+		git_config_set(cfg_name, "true");
+		free(cfg_name);
+	}
 
 	/*
 	 * Record the initial filter-spec in the config as
 	 * the default for subsequent fetches from this remote.
 	 */
-	core_partial_clone_filter_default =
-		xstrdup(filter_options->filter_spec);
-	git_config_set("core.partialclonefilter",
-		       core_partial_clone_filter_default);
+	filter_name = xstrfmt("remote.%s.partialclonefilter", remote);
+	/* NEEDSWORK: 'expand' result leaking??? */
+	git_config_set(filter_name,
+		       expand_list_objects_filter_spec(filter_options));
+	free(filter_name);
+
+	/* Make sure the config info are reset */
+	promisor_remote_reinit();
 }
 
 void partial_clone_get_default_filter_spec(
-	struct list_objects_filter_options *filter_options)
+	struct list_objects_filter_options *filter_options,
+	const char *remote)
 {
+	struct promisor_remote *promisor = promisor_remote_find(remote);
+	struct strbuf errbuf = STRBUF_INIT;
+
 	/*
 	 * Parse default value, but silently ignore it if it is invalid.
 	 */
-	if (!core_partial_clone_filter_default)
+	if (!promisor)
 		return;
+
+	string_list_append(&filter_options->filter_spec,
+			   promisor->partial_clone_filter);
 	gently_parse_list_objects_filter(filter_options,
-					 core_partial_clone_filter_default,
-					 NULL);
+					 promisor->partial_clone_filter,
+					 &errbuf);
+	strbuf_release(&errbuf);
 }