ruby/lib/rubygems/package/tar_reader.rb
Martin Emde e913431687 [rubygems/rubygems] Raise Gem::Package::FormatError on EOF, indicating corrupt gem
Gem::Package::TarReader::Entry now raises EOFError or returns nil
appropriately based on Ruby core IO.read and IO.readpartial behavior.

Zlib will respond accordingly by raising Zlib::GzipFile::Error on EOF.

When verifying a gem or extracting contents, raise FormatError similar
to other cases of corrupt gems.

Addresses a bug where Gem::Package would attempt to call size on nil
instead of raising a more descriptive and useful error, leading users
to assume the problem is internal to rubygems.

Remove unused error class TarReader::UnexpectedEOF that was never raised
since the NoMethodError on nil would happen first. Use EOFError instead.

dc6129644b
2023-08-17 23:16:57 +00:00

94 lines
1.7 KiB
Ruby

# frozen_string_literal: true
# rubocop:disable Style/AsciiComments
# Copyright (C) 2004 Mauricio Julio Fernández Pradier
# See LICENSE.txt for additional licensing information.
# rubocop:enable Style/AsciiComments
##
# TarReader reads tar files and allows iteration over their items
class Gem::Package::TarReader
include Enumerable
##
# Creates a new TarReader on +io+ and yields it to the block, if given.
def self.new(io)
reader = super
return reader unless block_given?
begin
yield reader
ensure
reader.close
end
nil
end
##
# Creates a new tar file reader on +io+ which needs to respond to #pos,
# #eof?, #read, #getc and #pos=
def initialize(io)
@io = io
@init_pos = io.pos
end
##
# Close the tar file
def close
end
##
# Iterates over files in the tarball yielding each entry
def each
return enum_for __method__ unless block_given?
until @io.eof? do
header = Gem::Package::TarHeader.from @io
return if header.empty?
entry = Gem::Package::TarReader::Entry.new header, @io
yield entry
entry.close
end
end
alias_method :each_entry, :each
##
# NOTE: Do not call #rewind during #each
def rewind
if @init_pos == 0
@io.rewind
else
@io.pos = @init_pos
end
end
##
# Seeks through the tar file until it finds the +entry+ with +name+ and
# yields it. Rewinds the tar file to the beginning when the block
# terminates.
def seek(name) # :yields: entry
found = find do |entry|
entry.full_name == name
end
return unless found
yield found
ensure
rewind
end
end
require_relative "tar_reader/entry"