Fixed initialization processing when reaching the end of a file in IOSource#read

[naitoh]

Why?

Avoid causing an error when @source.eof? is called after IOSource#read_until is invoked in subsequent processing.

/.gems/gems/rexml-3.4.2/lib/rexml/parsers/baseparser.rb:524:in 'REXML::Parsers::BaseParser#pull_event': #<NoMethodError: undefined method 'eof?' for nil> (REXML::ParseException)
.gems/gems/rexml-3.4.2/lib/rexml/source.rb:275:in 'REXML::IOSource#read_until'

rexml/lib/rexml/source.rb

Lines 266 to 276 in 185bdc7

	def read_until(term)
	pattern = Private::PRE_DEFINED_TERM_PATTERNS[term] || /#{Regexp.escape(term)}/
	term = @encoded_terms[term] ||= encode(term)
	until str = @scanner.scan_until(pattern)
	break if @source.nil?
	break if @source.eof?
	@scanner << readline(term)
	end
	if str
	read if @scanner.eos? and !@source.eof?
	str

See: #287