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# Note that this doesn't attempt to handle HT characters
def remove_indentation(s)
l = s.lines
indent = l.grep(/\S/).map {|l| l[/^\s*/].size}.min
l.map {|li| li.sub(/^ {0,#{indent}}/, "")}.join
end
def trim_empty_lines_around(s) # this deletes the trailing newline, which may need to be reconstructed
s.sub(/\A(\r?\n)*/, '').sub(/(\r?\n)*\z/, '')
end
def fix_unterminated_line(s)
s.sub(/[^\n]\z/) { "#$&\n" } # XXX
end
def handle_artwork_sourcecode(s, unfold = true)
s = trim_empty_lines_around(s)
s = unfold8792(s) if unfold
fix_unterminated_line(s)
end
FOLD_MSG = "NOTE: '\\' line wrapping per RFC 8792".freeze
UNFOLD_RE = /\A.*#{FOLD_MSG.sub("\\", "(\\\\\\\\\\\\\\\\?)")}.*\n\r?\n/
def unfold8792(s)
if s =~ UNFOLD_RE
indicator = $1
s = $'
sub = case indicator
when "\\"
s.gsub!(/\\\n[ \t]*/, '')
when "\\\\"
s.gsub!(/\\\n[ \t]*\\/, '')
else
fail "indicator" # Cannot happen
end
warn "** encountered RFC 8792 header without folded lines" unless sub
end
s
end
MIN_FOLD_COLUMNS = FOLD_MSG.size
FOLD_COLUMNS = 69
RE_IDENT = /\A[A-Za-z0-9_]\z/
def fold8792_1(s, columns = FOLD_COLUMNS, left = false, dry = false)
if s.index("\t")
warn "*** HT (\"TAB\") in text to be folded. Giving up."
return s
end
if columns < MIN_FOLD_COLUMNS
columns =
if columns == 0
FOLD_COLUMNS
else
warn "*** folding to #{MIN_FOLD_COLUMNS}, not #{columns}"
MIN_FOLD_COLUMNS
end
end
lines = s.lines.map(&:chomp)
did_fold = false
ix = 0
while li = lines[ix]
col = columns
if li[col].nil?
if li[-1] == "\\"
lines[ix..ix] = [li << "\\", ""]
ix += 1
end
ix += 1
else
did_fold = true
min_indent = left || 0
col -= 1 # space for "\\"
while li[col] == " " # can't start new line with " "
col -= 1
end
if col <= min_indent
warn "*** Cannot RFC8792-fold1 to #{columns} cols #{"with indent #{left}" if left} |#{li.inspect}|"
else
if RE_IDENT === li[col] # Don't split IDs
col2 = col
while col2 > min_indent && RE_IDENT === li[col2-1]
col2 -= 1
end
if col2 > min_indent
col = col2
end
end
rest = li[col..-1]
indent = left || columns - rest.size
if !left && li[-1] == "\\"
indent -= 1 # leave space for next round
end
if indent > 0
rest = " " * indent + rest
end
lines[ix..ix] = [li[0...col] << "\\", rest]
end
ix += 1
end
end
if did_fold
msg = FOLD_MSG.dup
if !dry && columns >= msg.size + 4
delta = columns - msg.size - 2 # 2 spaces
half = delta/2
msg = "#{"=" * half} #{msg} #{"=" * (delta - half)}"
end
lines[0...0] = [msg, ""]
lines.map{|x| x << "\n"}.join
else
s
end
end
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