fix: allow '~' in emitted anchor and alias names#1461
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IsAnchorChar rejected 0x7E ('~') via an off-by-one (< 0x7E), even though
'~' is a valid ns-char and the parser's anchor rule already accepts it.
As a result the emitter could not round-trip its own valid anchor names,
failing with INVALID_ANCHOR. DEL (0x7F) and C1 controls stay excluded.
Collaborator
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Nice find! Could you provida a link to the yaml-specs which defines the printable range? |
Contributor
Author
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Sure — https://yaml.org/spec/1.2.2/#character-set
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IsAnchorChar(the emitter'sns-anchor-charcheck) rejects0x7E(~) because of an off-by-one: it testsch < 0x7Ebefore falling through to the DEL/C1 exclusion. But~is a validns-char(YAML 1.2 printable range0x21–0x7E) and is not a flow indicator, so it's a legal anchor-name character — and the scanner's anchor rule (Exp::Anchor()) already accepts it.The result is an asymmetry:
&anchor~ xparses fine but the emitter can't write it back out, failing withINVALID_ANCHOR— so yaml-cpp fails to round-trip its own valid input.Fix:
ch < 0x7E→ch <= 0x7E. DEL (0x7F) and the C1 controls (0x80–0x9F) remain excluded. AddedEmitterTest.AnchorWithTilde(fails before, passes after).