fix(util): escape null byte unambiguously in quote()#1492
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In bash ANSI-C quoting ($'...'), \0 is a variable-length octal escape that
greedily consumes up to three following octal digits. Emitting a NUL as \0
therefore merges with subsequent digits: quote('\0' + '123') produced
$'\0123', which bash reads as octal \012 (newline) followed by '3' instead of
NUL followed by '123'. Emitting a fixed three-digit \000 keeps the escape
unambiguous, since bash octal escapes are at most three digits.
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Description
quote()escapes a NUL byte as\0. In bash ANSI-C quoting ($'...'),\0is a variable-length octal escape that greedily absorbs up to three following octal digits. So a NUL followed by octal digits is misdecoded.Bash reads
$'\0123'as\012(octal for newline,0x0a) followed by3. The intended NUL is silently turned into a newline and the following123is corrupted. Confirmed end to end through zx:$`printf '%s' ${'a\0123'}`yields the bytesa,0x0a,3instead of a clean value.Fix
Emit a fixed three-digit octal
\000instead of\0. Bash octal escapes are at most three digits, so\000cannot absorb following digits and the value stays intact.Test
Extended the
quote()null-byte case intest/util.test.js. It fails before the change ($'\0123', ambiguous) and passes after ($'\000123').