When parsing YAML with empty map values followed by blank lines, stringification would double the blank lines. The parsed document's spaceBefore property was being incorrectly interpreted during stringify, adding an extra newline on top of the existing one.

const yaml = `map:
  item:

anothermap:
  anotheritem:
`;

parseDocument(yaml).toString()
// Before: "map:\n  item:\n\n\nanothermap:\n  anotheritem:\n\n\n" (doubled blank lines)
// After:  "map:\n  item:\n\nanothermap:\n  anotheritem:\n\n" (preserved correctly)

Changes

• src/stringify/stringifyPair.ts: Removed the newline-doubling logic for empty values with spaceBefore. The property already represents the blank line; doubling creates an extra one. Exception: empty values with inline comments still get the double newline to preserve blank line before comment.

• tests/issue-474.test.ts: Added tests covering empty values with blank lines and nested structures.

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