Merge branch 'jt/archive-zip-deflate-fix' into next

The deflate codepath in "git archive --format=zip" had a
longstanding bug coming from misuse of zlib API, which has been
corrected.

* jt/archive-zip-deflate-fix:
  archive: flush deflate stream until Z_STREAM_END

Author: gitster

archive-zip.c

@@ -492,14 +492,22 @@ static int write_zip_entry(struct archiver_args *args,
 
 		zstream.next_in = buf;
 		zstream.avail_in = 0;
-		result = git_deflate(&zstream, Z_FINISH);
-		if (result != Z_STREAM_END)
-			die("deflate error (%d)", result);
+
+		do {
+			result = git_deflate(&zstream, Z_FINISH);
+			if (result != Z_OK && result != Z_STREAM_END)
+				die("deflate error (%d)", result);
+
+			out_len = zstream.next_out - compressed;
+			if (out_len > 0) {
+				write_or_die(1, compressed, out_len);
+				compressed_size += out_len;
+				zstream.next_out = compressed;
+				zstream.avail_out = sizeof(compressed);
+			}
+		} while (result != Z_STREAM_END);
 
 		git_deflate_end(&zstream);
-		out_len = zstream.next_out - compressed;
-		write_or_die(1, compressed, out_len);
-		compressed_size += out_len;
 		zip_offset += compressed_size;
 
 		write_zip_data_desc(size, compressed_size, crc);