[rudycelekli]

Pull Request

Description

The refusal names a character that is not in the name

ValidateName walks the name byte by byte — correctly, that loop is the confinement boundary — but reported the offending character as string(name[i]). Converting a byte to a string yields the code point of the same value, so the first byte of 語 (0xE8) was rendered as è:

before: invalid script name "語": character "è" is not allowed (names are 1-64 characters of A-Z, a-z, 0-9, '-' or '_' …)
after:  invalid script name "語": character "語" is not allowed (names are 1-64 characters of A-Z, a-z, 0-9, '-' or '_' …)

A caller is told to remove a character it never sent. A byte that begins no valid rune is not a character at all, and is now reported as one:

before: invalid script name "a\x80b": character "\u0080" is not allowed …
after:  invalid script name "a\x80b": byte 0x80 is not allowed …

Reachability. codescripts.Resolve / ResolveScoped call ValidateName before any filesystem access (codescripts.go:394), and internal/httpapi/code_exec.go:244 maps *InvalidNameError straight to an HTTP 400 INVALID_SCRIPT_NAME whose message body is invalidName.Error(). So any code_execution call naming a non-ASCII script — i.e. the exact case the validator is there to refuse — returns this message to the agent. The input is one the caller chooses freely; nothing upstream narrows it to ASCII first.

Note the order of the checks: the byte-length check fires first, so the mojibake path needs a short non-ASCII name (語 is 3 bytes, under the 64 limit) and the echo path below needs a long one. Both are ordinary requests.

The echoed name is cut inside a rune

truncateForMessage bounds the echoed name at MaxNameLen+16 bytes with a raw byte slice. For a long non-ASCII name the cut lands inside a rune and %q then renders the dangling bytes as \xNN escapes, so the refusal ends in hex noise instead of the name it is quoting. It now goes through stringutil.UTF8Prefix, the helper added in #1664 (see also #1647, #1665, and #1726 / #1727 which finish that sweep elsewhere).

The byte-wise validation loop, the confinement property and every ASCII refusal are unchanged.

One thing I did not change

len(name) > MaxNameLen is a byte check, while MaxNameLen is documented and reported as a character count ("names are 1-64 characters"). They agree for every name the token can accept, since a valid name is ASCII — but a 30-character Japanese name is refused as "name is 90 characters long", which reads as a contradiction against a 64-character limit. Reporting the rune count instead makes it worse ("name is 30 characters long" against a 64-character limit), because the real divergence is in the check, not the message. That is a product decision about whether the limit is bytes or characters, so I left it exactly as it is rather than guess. Happy to follow up either way.

Testing

• I have tested these changes locally
• I have added/updated tests that prove my fix is effective or my feature works
• All existing tests pass

New tests in internal/codescripts/invalid_name_message_test.go:

Test	Asserts
TestInvalidNameErrorNamesTheRealCharacter	the refusal contains 語 and does not contain è
TestInvalidNameErrorReportsMalformedByte	a stray 0x80 is reported as byte 0x80
TestInvalidNameErrorEchoIsNotCutInsideARune	3 byte offsets inside a 3-byte rune; no \x escape survives in the echo
TestValidateNameASCIIMessagesUnchanged	pins the full text of the empty / disallowed-character / oversized ASCII refusals, and that a valid name is still accepted

Mutation check. With internal/codescripts/codescripts.go reverted to the base SHA (14cb288) and the test file kept, the first three fail by name and TestValidateNameASCIIMessagesUnchanged passes — which is what shows the change is behaviour-preserving for ASCII. With the fix applied all four pass.

Commands run (exit status in brackets):

gofmt -l internal/codescripts          [0, no output]
git diff --check                        [0]
go vet ./internal/codescripts           [0]
go test -count=1 ./internal/codescripts [0, whole package]

Not run: -race and ./scripts/run-all-tests.sh (local disk constraints on this machine). Nothing here is concurrent.

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[Dumbris]

Verified on a merge with main: build, CI lint config, race tests; cross-reviewed clean.

[Dumbris]

Merged. Thank you, @rudycelekli! The refusal now names the character that is actually in the script name instead of the first byte of it, which is exactly the detail someone hits first when a name is non-ASCII.

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