Merge branch 'rs/large-zip'

"git archive --format=zip" learned to use zip64 extension when
necessary to go beyond the 4GB limit.

* rs/large-zip:
  t5004: require 64-bit support for big ZIP tests
  archive-zip: set version field for big files correctly
  archive-zip: support files bigger than 4GB
  archive-zip: support archives bigger than 4GB
  archive-zip: write ZIP dir entry directly to strbuf
  archive-zip: use strbuf for ZIP directory
  archive-zip: add tests for big ZIP archives

3 files changed, 181 insertions, 84 deletions

diff --git a/archive-zip.c b/archive-zip.c
index b429a8d974..e81c5ac15a 100644
--- a/archive-zip.c
+++ b/archive-zip.c
@@ -11,16 +11,14 @@
 static int zip_date;
 static int zip_time;
 
-static unsigned char *zip_dir;
-static unsigned int zip_dir_size;
+/* We only care about the "buf" part here. */
+static struct strbuf zip_dir;
 
-static unsigned int zip_offset;
-static unsigned int zip_dir_offset;
+static uintmax_t zip_offset;
 static uint64_t zip_dir_entries;
 
 static unsigned int max_creator_version;
 
-#define ZIP_DIRECTORY_MIN_SIZE	(1024 * 1024)
 #define ZIP_STREAM	(1 <<  3)
 #define ZIP_UTF8	(1 << 11)
 
@@ -47,24 +45,11 @@ struct zip_data_desc {
 	unsigned char _end[1];
 };
 
-struct zip_dir_header {
+struct zip64_data_desc {
 	unsigned char magic[4];
-	unsigned char creator_version[2];
-	unsigned char version[2];
-	unsigned char flags[2];
-	unsigned char compression_method[2];
-	unsigned char mtime[2];
-	unsigned char mdate[2];
 	unsigned char crc32[4];
-	unsigned char compressed_size[4];
-	unsigned char size[4];
-	unsigned char filename_length[2];
-	unsigned char extra_length[2];
-	unsigned char comment_length[2];
-	unsigned char disk[2];
-	unsigned char attr1[2];
-	unsigned char attr2[4];
-	unsigned char offset[4];
+	unsigned char compressed_size[8];
+	unsigned char size[8];
 	unsigned char _end[1];
 };
 
@@ -88,6 +73,14 @@ struct zip_extra_mtime {
 	unsigned char _end[1];
 };
 
+struct zip64_extra {
+	unsigned char magic[2];
+	unsigned char extra_size[2];
+	unsigned char size[8];
+	unsigned char compressed_size[8];
+	unsigned char _end[1];
+};
+
 struct zip64_dir_trailer {
 	unsigned char magic[4];
 	unsigned char record_size[8];
@@ -117,11 +110,15 @@ struct zip64_dir_trailer_locator {
  */
 #define ZIP_LOCAL_HEADER_SIZE	offsetof(struct zip_local_header, _end)
 #define ZIP_DATA_DESC_SIZE	offsetof(struct zip_data_desc, _end)
+#define ZIP64_DATA_DESC_SIZE	offsetof(struct zip64_data_desc, _end)
 #define ZIP_DIR_HEADER_SIZE	offsetof(struct zip_dir_header, _end)
 #define ZIP_DIR_TRAILER_SIZE	offsetof(struct zip_dir_trailer, _end)
 #define ZIP_EXTRA_MTIME_SIZE	offsetof(struct zip_extra_mtime, _end)
 #define ZIP_EXTRA_MTIME_PAYLOAD_SIZE \
 	(ZIP_EXTRA_MTIME_SIZE - offsetof(struct zip_extra_mtime, flags))
+#define ZIP64_EXTRA_SIZE	offsetof(struct zip64_extra, _end)
+#define ZIP64_EXTRA_PAYLOAD_SIZE \
+	(ZIP64_EXTRA_SIZE - offsetof(struct zip64_extra, size))
 #define ZIP64_DIR_TRAILER_SIZE	offsetof(struct zip64_dir_trailer, _end)
 #define ZIP64_DIR_TRAILER_RECORD_SIZE \
 	(ZIP64_DIR_TRAILER_SIZE - \
@@ -168,6 +165,26 @@ static void copy_le16_clamp(unsigned char *dest, uint64_t n, int *clamped)
 	copy_le16(dest, clamp_max(n, 0xffff, clamped));
 }
 
+static void copy_le32_clamp(unsigned char *dest, uint64_t n, int *clamped)
+{
+	copy_le32(dest, clamp_max(n, 0xffffffff, clamped));
+}
+
+static int strbuf_add_le(struct strbuf *sb, size_t size, uintmax_t n)
+{
+	while (size-- > 0) {
+		strbuf_addch(sb, n & 0xff);
+		n >>= 8;
+	}
+	return -!!n;
+}
+
+static uint32_t clamp32(uintmax_t n)
+{
+	const uintmax_t max = 0xffffffff;
+	return (n < max) ? n : max;
+}
+
 static void *zlib_deflate_raw(void *data, unsigned long size,
 			      int compression_level,
 			      unsigned long *compressed_size)
@@ -205,23 +222,23 @@ static void write_zip_data_desc(unsigned long size,
 				unsigned long compressed_size,
 				unsigned long crc)
 {
-	struct zip_data_desc trailer;
-
-	copy_le32(trailer.magic, 0x08074b50);
-	copy_le32(trailer.crc32, crc);
-	copy_le32(trailer.compressed_size, compressed_size);
-	copy_le32(trailer.size, size);
-	write_or_die(1, &trailer, ZIP_DATA_DESC_SIZE);
-}
-
-static void set_zip_dir_data_desc(struct zip_dir_header *header,
-				  unsigned long size,
-				  unsigned long compressed_size,
-				  unsigned long crc)
-{
-	copy_le32(header->crc32, crc);
-	copy_le32(header->compressed_size, compressed_size);
-	copy_le32(header->size, size);
+	if (size >= 0xffffffff || compressed_size >= 0xffffffff) {
+		struct zip64_data_desc trailer;
+		copy_le32(trailer.magic, 0x08074b50);
+		copy_le32(trailer.crc32, crc);
+		copy_le64(trailer.compressed_size, compressed_size);
+		copy_le64(trailer.size, size);
+		write_or_die(1, &trailer, ZIP64_DATA_DESC_SIZE);
+		zip_offset += ZIP64_DATA_DESC_SIZE;
+	} else {
+		struct zip_data_desc trailer;
+		copy_le32(trailer.magic, 0x08074b50);
+		copy_le32(trailer.crc32, crc);
+		copy_le32(trailer.compressed_size, compressed_size);
+		copy_le32(trailer.size, size);
+		write_or_die(1, &trailer, ZIP_DATA_DESC_SIZE);
+		zip_offset += ZIP_DATA_DESC_SIZE;
+	}
 }
 
 static void set_zip_header_data_desc(struct zip_local_header *header,
@@ -263,12 +280,14 @@ static int write_zip_entry(struct archiver_args *args,
 			   unsigned int mode)
 {
 	struct zip_local_header header;
-	struct zip_dir_header dirent;
+	uintmax_t offset = zip_offset;
 	struct zip_extra_mtime extra;
+	struct zip64_extra extra64;
+	size_t header_extra_size = ZIP_EXTRA_MTIME_SIZE;
+	int need_zip64_extra = 0;
 	unsigned long attr2;
 	unsigned long compressed_size;
 	unsigned long crc;
-	unsigned long direntsize;
 	int method;
 	unsigned char *out;
 	void *deflated = NULL;
@@ -279,6 +298,9 @@ static int write_zip_entry(struct archiver_args *args,
 	int is_binary = -1;
 	const char *path_without_prefix = path + args->baselen;
 	unsigned int creator_version = 0;
+	unsigned int version_needed = 10;
+	size_t zip_dir_extra_size = ZIP_EXTRA_MTIME_SIZE;
+	size_t zip64_dir_extra_payload_size = 0;
 
 	crc = crc32(0, NULL, 0);
 
@@ -356,43 +378,43 @@ static int write_zip_entry(struct archiver_args *args,
 	extra.flags[0] = 1;	/* just mtime */
 	copy_le32(extra.mtime, args->time);
 
-	/* make sure we have enough free space in the dictionary */
-	direntsize = ZIP_DIR_HEADER_SIZE + pathlen + ZIP_EXTRA_MTIME_SIZE;
-	while (zip_dir_size < zip_dir_offset + direntsize) {
-		zip_dir_size += ZIP_DIRECTORY_MIN_SIZE;
-		zip_dir = xrealloc(zip_dir, zip_dir_size);
-	}
+	if (size > 0xffffffff || compressed_size > 0xffffffff)
+		need_zip64_extra = 1;
+	if (stream && size > 0x7fffffff)
+		need_zip64_extra = 1;
 
-	copy_le32(dirent.magic, 0x02014b50);
-	copy_le16(dirent.creator_version, creator_version);
-	copy_le16(dirent.version, 10);
-	copy_le16(dirent.flags, flags);
-	copy_le16(dirent.compression_method, method);
-	copy_le16(dirent.mtime, zip_time);
-	copy_le16(dirent.mdate, zip_date);
-	set_zip_dir_data_desc(&dirent, size, compressed_size, crc);
-	copy_le16(dirent.filename_length, pathlen);
-	copy_le16(dirent.extra_length, ZIP_EXTRA_MTIME_SIZE);
-	copy_le16(dirent.comment_length, 0);
-	copy_le16(dirent.disk, 0);
-	copy_le32(dirent.attr2, attr2);
-	copy_le32(dirent.offset, zip_offset);
+	if (need_zip64_extra)
+		version_needed = 45;
 
 	copy_le32(header.magic, 0x04034b50);
-	copy_le16(header.version, 10);
+	copy_le16(header.version, version_needed);
 	copy_le16(header.flags, flags);
 	copy_le16(header.compression_method, method);
 	copy_le16(header.mtime, zip_time);
 	copy_le16(header.mdate, zip_date);
-	set_zip_header_data_desc(&header, size, compressed_size, crc);
+	if (need_zip64_extra) {
+		set_zip_header_data_desc(&header, 0xffffffff, 0xffffffff, crc);
+		header_extra_size += ZIP64_EXTRA_SIZE;
+	} else {
+		set_zip_header_data_desc(&header, size, compressed_size, crc);
+	}
 	copy_le16(header.filename_length, pathlen);
-	copy_le16(header.extra_length, ZIP_EXTRA_MTIME_SIZE);
+	copy_le16(header.extra_length, header_extra_size);
 	write_or_die(1, &header, ZIP_LOCAL_HEADER_SIZE);
 	zip_offset += ZIP_LOCAL_HEADER_SIZE;
 	write_or_die(1, path, pathlen);
 	zip_offset += pathlen;
 	write_or_die(1, &extra, ZIP_EXTRA_MTIME_SIZE);
 	zip_offset += ZIP_EXTRA_MTIME_SIZE;
+	if (need_zip64_extra) {
+		copy_le16(extra64.magic, 0x0001);
+		copy_le16(extra64.extra_size, ZIP64_EXTRA_PAYLOAD_SIZE);
+		copy_le64(extra64.size, size);
+		copy_le64(extra64.compressed_size, compressed_size);
+		write_or_die(1, &extra64, ZIP64_EXTRA_SIZE);
+		zip_offset += ZIP64_EXTRA_SIZE;
+	}
+
 	if (stream && method == 0) {
 		unsigned char buf[STREAM_BUFFER_SIZE];
 		ssize_t readlen;
@@ -415,9 +437,6 @@ static int write_zip_entry(struct archiver_args *args,
 		zip_offset += compressed_size;
 
 		write_zip_data_desc(size, compressed_size, crc);
-		zip_offset += ZIP_DATA_DESC_SIZE;
-
-		set_zip_dir_data_desc(&dirent, size, compressed_size, crc);
 	} else if (stream && method == 8) {
 		unsigned char buf[STREAM_BUFFER_SIZE];
 		ssize_t readlen;
@@ -473,9 +492,6 @@ static int write_zip_entry(struct archiver_args *args,
 		zip_offset += compressed_size;
 
 		write_zip_data_desc(size, compressed_size, crc);
-		zip_offset += ZIP_DATA_DESC_SIZE;
-
-		set_zip_dir_data_desc(&dirent, size, compressed_size, crc);
 	} else if (compressed_size > 0) {
 		write_or_die(1, out, compressed_size);
 		zip_offset += compressed_size;
@@ -484,14 +500,46 @@ static int write_zip_entry(struct archiver_args *args,
 	free(deflated);
 	free(buffer);
 
-	copy_le16(dirent.attr1, !is_binary);
+	if (compressed_size > 0xffffffff || size > 0xffffffff ||
+	    offset > 0xffffffff) {
+		if (compressed_size >= 0xffffffff)
+			zip64_dir_extra_payload_size += 8;
+		if (size >= 0xffffffff)
+			zip64_dir_extra_payload_size += 8;
+		if (offset >= 0xffffffff)
+			zip64_dir_extra_payload_size += 8;
+		zip_dir_extra_size += 2 + 2 + zip64_dir_extra_payload_size;
+	}
 
-	memcpy(zip_dir + zip_dir_offset, &dirent, ZIP_DIR_HEADER_SIZE);
-	zip_dir_offset += ZIP_DIR_HEADER_SIZE;
-	memcpy(zip_dir + zip_dir_offset, path, pathlen);
-	zip_dir_offset += pathlen;
-	memcpy(zip_dir + zip_dir_offset, &extra, ZIP_EXTRA_MTIME_SIZE);
-	zip_dir_offset += ZIP_EXTRA_MTIME_SIZE;
+	strbuf_add_le(&zip_dir, 4, 0x02014b50);	/* magic */
+	strbuf_add_le(&zip_dir, 2, creator_version);
+	strbuf_add_le(&zip_dir, 2, version_needed);
+	strbuf_add_le(&zip_dir, 2, flags);
+	strbuf_add_le(&zip_dir, 2, method);
+	strbuf_add_le(&zip_dir, 2, zip_time);
+	strbuf_add_le(&zip_dir, 2, zip_date);
+	strbuf_add_le(&zip_dir, 4, crc);
+	strbuf_add_le(&zip_dir, 4, clamp32(compressed_size));
+	strbuf_add_le(&zip_dir, 4, clamp32(size));
+	strbuf_add_le(&zip_dir, 2, pathlen);
+	strbuf_add_le(&zip_dir, 2, zip_dir_extra_size);
+	strbuf_add_le(&zip_dir, 2, 0);		/* comment length */
+	strbuf_add_le(&zip_dir, 2, 0);		/* disk */
+	strbuf_add_le(&zip_dir, 2, !is_binary);
+	strbuf_add_le(&zip_dir, 4, attr2);
+	strbuf_add_le(&zip_dir, 4, clamp32(offset));
+	strbuf_add(&zip_dir, path, pathlen);
+	strbuf_add(&zip_dir, &extra, ZIP_EXTRA_MTIME_SIZE);
+	if (zip64_dir_extra_payload_size) {
+		strbuf_add_le(&zip_dir, 2, 0x0001);	/* magic */
+		strbuf_add_le(&zip_dir, 2, zip64_dir_extra_payload_size);
+		if (size >= 0xffffffff)
+			strbuf_add_le(&zip_dir, 8, size);
+		if (compressed_size >= 0xffffffff)
+			strbuf_add_le(&zip_dir, 8, compressed_size);
+		if (offset >= 0xffffffff)
+			strbuf_add_le(&zip_dir, 8, offset);
+	}
 	zip_dir_entries++;
 
 	return 0;
@@ -510,12 +558,12 @@ static void write_zip64_trailer(void)
 	copy_le32(trailer64.directory_start_disk, 0);
 	copy_le64(trailer64.entries_on_this_disk, zip_dir_entries);
 	copy_le64(trailer64.entries, zip_dir_entries);
-	copy_le64(trailer64.size, zip_dir_offset);
+	copy_le64(trailer64.size, zip_dir.len);
 	copy_le64(trailer64.offset, zip_offset);
 
 	copy_le32(locator64.magic, 0x07064b50);
 	copy_le32(locator64.disk, 0);
-	copy_le64(locator64.offset, zip_offset + zip_dir_offset);
+	copy_le64(locator64.offset, zip_offset + zip_dir.len);
 	copy_le32(locator64.number_of_disks, 1);
 
 	write_or_die(1, &trailer64, ZIP64_DIR_TRAILER_SIZE);
@@ -533,11 +581,11 @@ static void write_zip_trailer(const unsigned char *sha1)
 	copy_le16_clamp(trailer.entries_on_this_disk, zip_dir_entries,
 			&clamped);
 	copy_le16_clamp(trailer.entries, zip_dir_entries, &clamped);
-	copy_le32(trailer.size, zip_dir_offset);
-	copy_le32(trailer.offset, zip_offset);
+	copy_le32(trailer.size, zip_dir.len);
+	copy_le32_clamp(trailer.offset, zip_offset, &clamped);
 	copy_le16(trailer.comment_length, sha1 ? GIT_SHA1_HEXSZ : 0);
 
-	write_or_die(1, zip_dir, zip_dir_offset);
+	write_or_die(1, zip_dir.buf, zip_dir.len);
 	if (clamped)
 		write_zip64_trailer();
 	write_or_die(1, &trailer, ZIP_DIR_TRAILER_SIZE);
@@ -568,14 +616,13 @@ static int write_zip_archive(const struct archiver *ar,
 
 	dos_time(&args->time, &zip_date, &zip_time);
 
-	zip_dir = xmalloc(ZIP_DIRECTORY_MIN_SIZE);
-	zip_dir_size = ZIP_DIRECTORY_MIN_SIZE;
+	strbuf_init(&zip_dir, 0);
 
 	err = write_archive_entries(args, write_zip_entry);
 	if (!err)
 		write_zip_trailer(args->commit_sha1);
 
-	free(zip_dir);
+	strbuf_release(&zip_dir);
 
 	return err;
 }
diff --git a/t/t5004-archive-corner-cases.sh b/t/t5004-archive-corner-cases.sh
index cca23383c5..f6207f42b5 100755
--- a/t/t5004-archive-corner-cases.sh
+++ b/t/t5004-archive-corner-cases.sh
@@ -27,6 +27,9 @@ check_dir() {
 	test_cmp expect actual
 }
 
+test_lazy_prereq UNZIP_ZIP64_SUPPORT '
+	"$GIT_UNZIP" -v | grep ZIP64_SUPPORT
+'
 
 # bsdtar/libarchive versions before 3.1.3 consider a tar file with a
 # global pax header that is not followed by a file record as corrupt.
@@ -155,4 +158,51 @@ test_expect_success ZIPINFO 'zip archive with many entries' '
 	test_cmp expect actual
 '
 
+test_expect_success EXPENSIVE,UNZIP,UNZIP_ZIP64_SUPPORT \
+	'zip archive bigger than 4GB' '
+	# build string containing 65536 characters
+	s=0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef &&
+	s=$s$s$s$s$s$s$s$s$s$s$s$s$s$s$s$s$s$s$s$s$s$s$s$s$s$s$s$s$s$s$s$s &&
+	s=$s$s$s$s$s$s$s$s$s$s$s$s$s$s$s$s$s$s$s$s$s$s$s$s$s$s$s$s$s$s$s$s &&
+
+	# create blob with a length of 65536 + 1 bytes
+	blob=$(echo $s | git hash-object -w --stdin) &&
+
+	# create tree containing 65500 entries of that blob
+	for i in $(test_seq 1 65500)
+	do
+		echo "100644 blob $blob	$i"
+	done >tree &&
+	tree=$(git mktree <tree) &&
+
+	# zip it, creating an archive a bit bigger than 4GB
+	git archive -0 -o many-big.zip $tree &&
+
+	"$GIT_UNZIP" -t many-big.zip 9999 65500 &&
+	"$GIT_UNZIP" -t many-big.zip
+'
+
+test_expect_success EXPENSIVE,LONG_IS_64BIT,UNZIP,UNZIP_ZIP64_SUPPORT,ZIPINFO \
+	'zip archive with files bigger than 4GB' '
+	# Pack created with:
+	#   dd if=/dev/zero of=file bs=1M count=4100 && git hash-object -w file
+	mkdir -p .git/objects/pack &&
+	(
+		cd .git/objects/pack &&
+		"$GIT_UNZIP" "$TEST_DIRECTORY"/t5004/big-pack.zip
+	) &&
+	blob=754a93d6fada4c6873360e6cb4b209132271ab0e &&
+	size=$(expr 4100 "*" 1024 "*" 1024) &&
+
+	# create a tree containing the file
+	tree=$(echo "100644 blob $blob	big-file" | git mktree) &&
+
+	# zip it, creating an archive with a file bigger than 4GB
+	git archive -o big.zip $tree &&
+
+	"$GIT_UNZIP" -t big.zip &&
+	"$ZIPINFO" big.zip >big.lst &&
+	grep $size big.lst
+'
+
 test_done
diff --git a/t/t5004/big-pack.zip b/t/t5004/big-pack.zip
new file mode 100644
index 0000000000..caaf614eee
--- /dev/null
+++ b/t/t5004/big-pack.zip