🐛 Fix #header_fld_name to handle quoted strings correctly

[taku0]

Summary

If a header field name is quoted, ResponseParser#header_fld_name drops the closing quotation mark.

Reprodusing code

parser = Net::IMAP::ResponseParser.new

parser.instance_variable_set("@str", %Q|"CONTENT-LOCATION")|)
parser.instance_variable_set("@pos", 0)
parser.instance_variable_set("@lex_state", Net::IMAP::ResponseParser::EXPR_BEG)

parser.send(:header_fld_name)

Expected: "\"CONTENT-LOCATION\""
Actual: "\"CONTENT-LOCATION"

Cause

header_fld_name extract the raw encoded value using @str and @pos. header_fld_name expects astring to lookahead a space or a closing parenthesis but if the field name is quoted, it calls string method and it doesn't lookahead a token.

Fix

Adjust the range to extract depending on whether a token is looked ahead or not.

[nevans]

Good catch. Thanks! I'll merge and release it on Monday or Tuesday.

Could you add a simple test case to test/net/imap/fixtures/response_parser/fetch_responses.yml? If you add the test case without any "expected" value, the test runner will print out the actual parsed result, for you to inspect and copy/paste into the yaml. Thanks!

[taku0]

I have amended the commit with a test case.

[nevans]

@taku0 v0.4.16 has been released. Thanks again!