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, 18 insertions, 28 deletions

diff --git a/third_party/git/archive-tar.c b/third_party/git/archive-tar.c
index 3e53aac1e6..f1a1447ebd 100644
--- a/third_party/git/archive-tar.c
+++ b/third_party/git/archive-tar.c
@@ -112,7 +112,7 @@ static void write_trailer(void)
  * queues up writes, so that all our write(2) calls write exactly one
  * full block; pads writes to RECORDSIZE
  */
-static int stream_blocked(const struct object_id *oid)
+static int stream_blocked(struct repository *r, const struct object_id *oid)
 {
 	struct git_istream *st;
 	enum object_type type;
@@ -120,7 +120,7 @@ static int stream_blocked(const struct object_id *oid)
 	char buf[BLOCKSIZE];
 	ssize_t readlen;
 
-	st = open_istream(oid, &type, &sz, NULL);
+	st = open_istream(r, oid, &type, &sz, NULL);
 	if (!st)
 		return error(_("cannot stream blob %s"), oid_to_hex(oid));
 	for (;;) {
@@ -142,19 +142,25 @@ static int stream_blocked(const struct object_id *oid)
  * string and appends it to a struct strbuf.
  */
 static void strbuf_append_ext_header(struct strbuf *sb, const char *keyword,
-				     const char *value, unsigned int valuelen)
+				     const char *value, size_t valuelen)
 {
-	int len, tmp;
+	size_t orig_len = sb->len;
+	size_t len, tmp;
 
 	/* "%u %s=%s\n" */
 	len = 1 + 1 + strlen(keyword) + 1 + valuelen + 1;
-	for (tmp = len; tmp > 9; tmp /= 10)
+	for (tmp = 1; len / 10 >= tmp; tmp *= 10)
 		len++;
 
 	strbuf_grow(sb, len);
-	strbuf_addf(sb, "%u %s=", len, keyword);
+	strbuf_addf(sb, "%"PRIuMAX" %s=", (uintmax_t)len, keyword);
 	strbuf_add(sb, value, valuelen);
 	strbuf_addch(sb, '\n');
+
+	if (len != sb->len - orig_len)
+		BUG("pax extended header length miscalculated as %"PRIuMAX
+		    ", should be %"PRIuMAX,
+		    (uintmax_t)len, (uintmax_t)(sb->len - orig_len));
 }
 
 /*
@@ -236,13 +242,12 @@ static void write_extended_header(struct archiver_args *args,
 static int write_tar_entry(struct archiver_args *args,
 			   const struct object_id *oid,
 			   const char *path, size_t pathlen,
-			   unsigned int mode)
+			   unsigned int mode,
+			   void *buffer, unsigned long size)
 {
 	struct ustar_header header;
 	struct strbuf ext_header = STRBUF_INIT;
-	unsigned int old_mode = mode;
-	unsigned long size, size_in_header;
-	void *buffer;
+	unsigned long size_in_header;
 	int err = 0;
 
 	memset(&header, 0, sizeof(header));
@@ -276,20 +281,6 @@ static int write_tar_entry(struct archiver_args *args,
 	} else
 		memcpy(header.name, path, pathlen);
 
-	if (S_ISREG(mode) && !args->convert &&
-	    oid_object_info(args->repo, oid, &size) == OBJ_BLOB &&
-	    size > big_file_threshold)
-		buffer = NULL;
-	else if (S_ISLNK(mode) || S_ISREG(mode)) {
-		enum object_type type;
-		buffer = object_file_to_archive(args, path, oid, old_mode, &type, &size);
-		if (!buffer)
-			return error(_("cannot read %s"), oid_to_hex(oid));
-	} else {
-		buffer = NULL;
-		size = 0;
-	}
-
 	if (S_ISLNK(mode)) {
 		if (size > sizeof(header.linkname)) {
 			xsnprintf(header.linkname, sizeof(header.linkname),
@@ -318,9 +309,8 @@ static int write_tar_entry(struct archiver_args *args,
 		if (buffer)
 			write_blocked(buffer, size);
 		else
-			err = stream_blocked(oid);
+			err = stream_blocked(args->repo, oid);
 	}
-	free(buffer);
 	return err;
 }
 
@@ -358,7 +348,7 @@ static struct archiver **tar_filters;
 static int nr_tar_filters;
 static int alloc_tar_filters;
 
-static struct archiver *find_tar_filter(const char *name, int len)
+static struct archiver *find_tar_filter(const char *name, size_t len)
 {
 	int i;
 	for (i = 0; i < nr_tar_filters; i++) {
@@ -374,7 +364,7 @@ static int tar_filter_config(const char *var, const char *value, void *data)
 	struct archiver *ar;
 	const char *name;
 	const char *type;
-	int namelen;
+	size_t namelen;
 
 	if (parse_config_key(var, "tar", &name, &namelen, &type) < 0 || !name)
 		return 0;