Chomped literals with multiple newlines lose a line-break after a roundtrip

[iliakap]

The following example demonstrates the bug, this yaml:

a: |2-


  str

after a decode-encode cycle, one newline is lost and the output is:

a: |2-

  str

after another decode-encode cycle the output would be:

a: |2-
  str

and so on...

here's a test case that demonstrates the bug:

var nodeTests = []struct {
	yaml string
	node yaml.Node
}{
	{
		// multiline literal starting with multiple newlines.
		"a: |2-\n\n\n  str\n",
		yaml.Node{
			Kind:   yaml.DocumentNode,
			Line:   1,
			Column: 1,
			Content: []*yaml.Node{{
				Kind:   yaml.MappingNode,
				Tag:    "!!map",
				Line:   1,
				Column: 1,
				Content: []*yaml.Node{{
					Kind:   yaml.ScalarNode,
					Tag:    "!!str",
					Value:  "a",
					Line:   1,
					Column: 1,
				}, {
					Kind:        yaml.ScalarNode,
					Style:       yaml.LiteralStyle,
					Tag:         "!!str",
					Value:       "\n\nstr",
					LineComment: "",
					Line:        1,
					Column:      4,
				}},
			}},
		},
	},
}

[connesc]

This looks as a major issue, as it affects the actual value of the string field, not only its aesthetic. Also, aren't non-chomped literals affected too?

[iliakap]

@connesc Looks like it only affects literals with chomping, as they are handled slightly differently by the parser