2026-10-17 — Refines dcn-2610170704288549: the guard counts a { or } as opening or closing a group, for what a pipe into the group reaches, only where the line leaves that word wholly unquoted, the same test the approver's own reading of the text it hands back uses. A } with a quote in it, even an empty pair (}"" or }''), is a command's name to the shell, so the commands after it still read the group's piped input, and a shell among them is refused as one reading a stream (echo 'touch ran' | { }""; bash; } is refused, as the same line with true in place of the } is). And a removal or a write in a command where an unquoted ( stands in a word, glued to it (build/l(:A), x(.), a/b(/), a redirection's target) or opening one after the command's name, is refused as a target the line does not fix, whatever follows the (. zsh reads such a ( as glob qualifiers or modifiers that can change the path the word names: build/l(:A) is the real path a symlink leads to, outside the working tree; bash refuses the line. A find or an rsync in such a command is read as removing, since the words after the ( are not read as its own. A quoted or escaped ( is text and stays allowed (rm -f 'a(b)').

Frontmatter

.abcd/work/decisions/dcn-2610170726383253-refines-dcn-2610170704288549-the-guard.md
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mentions2

• dcn-26101707042885492026-10-17 — Refines dcn-2610170618185599: when the headless approver reads the text it hands back, it counts a { or a keyword as opening, closing or leading a command only where the line leaves that word wholly unquoted, with no quote, escape or empty quote pair in it, the same test it already applies to a }. A quoted { ("{", '{', \{, {"") or a quoted keyword ('then', \!, "time", 'function') is a command's name to the shell, and the words after it are arguments, so a line of one, then a }, then a command, is refused under tree-group-broken, since under bash and sh that } closes the group and the command after it runs outside the change of directory. And a glob removal is refused as a target the line does not fix when its pattern holds a /: a wildcard in a directory part (build/*/*, ./build/*/*, build/*/x.o) or a trailing / (build/*/). Such a glob lists directories the line never names, any of which may be a symlink out of the working tree, which the shell would expand into. This refusal was chosen over following every matching directory through symlinks, as the simpler rule; a glob whose wildcards stand only in its last name, such as rm -rf build/*, is judged as before.
• dcn-26101707391865432026-10-17 — Refines dcn-2610170726383253: a command where an unquoted ( stands in a word, glued to it or opening one after the command's name, is refused whole as one whose targets the line does not fix, whatever the command is, not only for the targets the guard reads. The words after the ( are not read as the command's own, so a flag there that makes it write (sed x(.) -i, cp a(.) -t dir) is not seen, and zsh may read the ( as glob qualifiers or modifiers that change the path a word names (echo hi(:A), ls x(/) are refused too). bash refuses every such line as a syntax error, so nothing a bash user runs is lost. A function definition's () after its name (f() { … }, f () { … }, function f() { … }) is not such a word and stays allowed, as does a quoted or escaped (.