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, 84 insertions, 22 deletions

diff --git a/third_party/git/bundle.c b/third_party/git/bundle.c
index b5d21cd80f..cb0e5931ac 100644
--- a/third_party/git/bundle.c
+++ b/third_party/git/bundle.c
@@ -10,9 +10,18 @@
 #include "list-objects.h"
 #include "run-command.h"
 #include "refs.h"
-#include "argv-array.h"
+#include "strvec.h"
 
-static const char bundle_signature[] = "# v2 git bundle\n";
+
+static const char v2_bundle_signature[] = "# v2 git bundle\n";
+static const char v3_bundle_signature[] = "# v3 git bundle\n";
+static struct {
+	int version;
+	const char *signature;
+} bundle_sigs[] = {
+	{ 2, v2_bundle_signature },
+	{ 3, v3_bundle_signature },
+};
 
 static void add_to_ref_list(const struct object_id *oid, const char *name,
 		struct ref_list *list)
@@ -23,6 +32,32 @@ static void add_to_ref_list(const struct object_id *oid, const char *name,
 	list->nr++;
 }
 
+static int parse_capability(struct bundle_header *header, const char *capability)
+{
+	const char *arg;
+	if (skip_prefix(capability, "object-format=", &arg)) {
+		int algo = hash_algo_by_name(arg);
+		if (algo == GIT_HASH_UNKNOWN)
+			return error(_("unrecognized bundle hash algorithm: %s"), arg);
+		header->hash_algo = &hash_algos[algo];
+		return 0;
+	}
+	return error(_("unknown capability '%s'"), capability);
+}
+
+static int parse_bundle_signature(struct bundle_header *header, const char *line)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(bundle_sigs); i++) {
+		if (!strcmp(line, bundle_sigs[i].signature)) {
+			header->version = bundle_sigs[i].version;
+			return 0;
+		}
+	}
+	return -1;
+}
+
 static int parse_bundle_header(int fd, struct bundle_header *header,
 			       const char *report_path)
 {
@@ -31,14 +66,16 @@ static int parse_bundle_header(int fd, struct bundle_header *header,
 
 	/* The bundle header begins with the signature */
 	if (strbuf_getwholeline_fd(&buf, fd, '\n') ||
-	    strcmp(buf.buf, bundle_signature)) {
+	    parse_bundle_signature(header, buf.buf)) {
 		if (report_path)
-			error(_("'%s' does not look like a v2 bundle file"),
+			error(_("'%s' does not look like a v2 or v3 bundle file"),
 			      report_path);
 		status = -1;
 		goto abort;
 	}
 
+	header->hash_algo = the_hash_algo;
+
 	/* The bundle header ends with an empty line */
 	while (!strbuf_getwholeline_fd(&buf, fd, '\n') &&
 	       buf.len && buf.buf[0] != '\n') {
@@ -46,18 +83,27 @@ static int parse_bundle_header(int fd, struct bundle_header *header,
 		int is_prereq = 0;
 		const char *p;
 
+		strbuf_rtrim(&buf);
+
+		if (header->version == 3 && *buf.buf == '@') {
+			if (parse_capability(header, buf.buf + 1)) {
+				status = -1;
+				break;
+			}
+			continue;
+		}
+
 		if (*buf.buf == '-') {
 			is_prereq = 1;
 			strbuf_remove(&buf, 0, 1);
 		}
-		strbuf_rtrim(&buf);
 
 		/*
 		 * Tip lines have object name, SP, and refname.
 		 * Prerequisites have object name that is optionally
 		 * followed by SP and subject line.
 		 */
-		if (parse_oid_hex(buf.buf, &oid, &p) ||
+		if (parse_oid_hex_algop(buf.buf, &oid, &p, header->hash_algo) ||
 		    (*p && !isspace(*p)) ||
 		    (!is_prereq && !*p)) {
 			if (report_path)
@@ -249,15 +295,16 @@ out:
 
 
 /* Write the pack data to bundle_fd */
-static int write_pack_data(int bundle_fd, struct rev_info *revs)
+static int write_pack_data(int bundle_fd, struct rev_info *revs, struct strvec *pack_options)
 {
 	struct child_process pack_objects = CHILD_PROCESS_INIT;
 	int i;
 
-	argv_array_pushl(&pack_objects.args,
-			 "pack-objects", "--all-progress-implied",
-			 "--stdout", "--thin", "--delta-base-offset",
-			 NULL);
+	strvec_pushl(&pack_objects.args,
+		     "pack-objects",
+		     "--stdout", "--thin", "--delta-base-offset",
+		     NULL);
+	strvec_pushv(&pack_objects.args, pack_options->v);
 	pack_objects.in = -1;
 	pack_objects.out = bundle_fd;
 	pack_objects.git_cmd = 1;
@@ -282,7 +329,7 @@ static int write_pack_data(int bundle_fd, struct rev_info *revs)
 		struct object *object = revs->pending.objects[i].item;
 		if (object->flags & UNINTERESTING)
 			write_or_die(pack_objects.in, "^", 1);
-		write_or_die(pack_objects.in, oid_to_hex(&object->oid), GIT_SHA1_HEXSZ);
+		write_or_die(pack_objects.in, oid_to_hex(&object->oid), the_hash_algo->hexsz);
 		write_or_die(pack_objects.in, "\n", 1);
 	}
 	close(pack_objects.in);
@@ -300,11 +347,11 @@ static int compute_and_write_prerequisites(int bundle_fd,
 	FILE *rls_fout;
 	int i;
 
-	argv_array_pushl(&rls.args,
-			 "rev-list", "--boundary", "--pretty=oneline",
-			 NULL);
+	strvec_pushl(&rls.args,
+		     "rev-list", "--boundary", "--pretty=oneline",
+		     NULL);
 	for (i = 1; i < argc; i++)
-		argv_array_push(&rls.args, argv[i]);
+		strvec_push(&rls.args, argv[i]);
 	rls.out = -1;
 	rls.git_cmd = 1;
 	if (start_command(&rls))
@@ -356,7 +403,7 @@ static int write_bundle_refs(int bundle_fd, struct rev_info *revs)
 
 		if (e->item->flags & UNINTERESTING)
 			continue;
-		if (dwim_ref(e->name, strlen(e->name), &oid, &ref) != 1)
+		if (dwim_ref(e->name, strlen(e->name), &oid, &ref, 0) != 1)
 			goto skip_write_ref;
 		if (read_ref_full(e->name, RESOLVE_REF_READING, &oid, &flag))
 			flag = 0;
@@ -414,7 +461,7 @@ static int write_bundle_refs(int bundle_fd, struct rev_info *revs)
 		}
 
 		ref_count++;
-		write_or_die(bundle_fd, oid_to_hex(&e->item->oid), 40);
+		write_or_die(bundle_fd, oid_to_hex(&e->item->oid), the_hash_algo->hexsz);
 		write_or_die(bundle_fd, " ", 1);
 		write_or_die(bundle_fd, display_ref, strlen(display_ref));
 		write_or_die(bundle_fd, "\n", 1);
@@ -428,13 +475,14 @@ static int write_bundle_refs(int bundle_fd, struct rev_info *revs)
 }
 
 int create_bundle(struct repository *r, const char *path,
-		  int argc, const char **argv)
+		  int argc, const char **argv, struct strvec *pack_options, int version)
 {
 	struct lock_file lock = LOCK_INIT;
 	int bundle_fd = -1;
 	int bundle_to_stdout;
 	int ref_count = 0;
 	struct rev_info revs;
+	int min_version = the_hash_algo == &hash_algos[GIT_HASH_SHA1] ? 2 : 3;
 
 	bundle_to_stdout = !strcmp(path, "-");
 	if (bundle_to_stdout)
@@ -443,8 +491,22 @@ int create_bundle(struct repository *r, const char *path,
 		bundle_fd = hold_lock_file_for_update(&lock, path,
 						      LOCK_DIE_ON_ERROR);
 
-	/* write signature */
-	write_or_die(bundle_fd, bundle_signature, strlen(bundle_signature));
+	if (version == -1)
+		version = min_version;
+
+	if (version < 2 || version > 3) {
+		die(_("unsupported bundle version %d"), version);
+	} else if (version < min_version) {
+		die(_("cannot write bundle version %d with algorithm %s"), version, the_hash_algo->name);
+	} else if (version == 2) {
+		write_or_die(bundle_fd, v2_bundle_signature, strlen(v2_bundle_signature));
+	} else {
+		const char *capability = "@object-format=";
+		write_or_die(bundle_fd, v3_bundle_signature, strlen(v3_bundle_signature));
+		write_or_die(bundle_fd, capability, strlen(capability));
+		write_or_die(bundle_fd, the_hash_algo->name, strlen(the_hash_algo->name));
+		write_or_die(bundle_fd, "\n", 1);
+	}
 
 	/* init revs to list objects for pack-objects later */
 	save_commit_buffer = 0;
@@ -470,7 +532,7 @@ int create_bundle(struct repository *r, const char *path,
 		goto err;
 
 	/* write pack */
-	if (write_pack_data(bundle_fd, &revs))
+	if (write_pack_data(bundle_fd, &revs, pack_options))
 		goto err;
 
 	if (!bundle_to_stdout) {