| Message ID | 9f37ae19-6f74-f527-aa49-dd04c3c010f6@gigawatt.nl (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Herbert Xu |
| Headers | show |
On Mon, Feb 19, 2018 at 11:13 PM, Harald van Dijk <harald@gigawatt.nl> wrote: > On 2/18/18 11:50 PM, Harald van Dijk wrote: >> On 2/14/18 11:50 PM, Harald van Dijk wrote: >>> On 2/14/18 10:44 PM, Harald van Dijk wrote: >>>> On 2/14/18 9:03 PM, Harald van Dijk wrote: >>>>> On 13/02/2018 14:53, Denys Vlasenko wrote: >>>>>> $ >'\zzzz' >>>>>> $ >'\wwww' >>>>>> $ dash -c 'echo "\*"' >>>>>> \wwww \zzzz >>>>> >>>>> >>>>> [...] >>>>> >>>>> Currently: >>>>> >>>>> $ dash -c 'foo=a; echo "<${foo#[a\]]}>"' >>>>> <> >>>>> >>>>> This is what I expect, and also what bash, ksh and posh do. >>>>> >>>>> With your patch: >>>>> >>>>> $ dash -c 'foo=a; echo "<${foo#[a\]]}>"' >>>>> <a> >>>> >>>> Does the attached look right as an alternative? It treats a quoted >>>> backslash the same way as if it were preceded by CTLESC in _rmescapes. It >>>> passes your test case and mine, but I'll do more extensive testing. >>> >>> It causes preglob's string to potentially grow larger than the original. >>> When called with RMESCAPE_ALLOC, that can be handled by increasing the >>> buffer size, but preglob also gets called without RMESCAPE_ALLOC to modify a >>> string in-place. That's never going to work with this approach. Back to the >>> drawing board... >> >> There is a way to make it work: ensure sufficient memory is always >> available. Instead of inserting CTLESC, which caused problems, >> CTLQUOTEMARK+CTLQUOTEMARK can be inserted instead. It's effectively a no-op >> here. > > It required one obvious additional trivial change to the CHECKSTRSPACE > invocation, but with that added, the attached passed all testing I could > think of. Does this look okay to include, did I miss something, or is there > perhaps a better alternative? I propose replacing this: if (*p == (char)CTLESC) { p++; + goto escape; + } else if (*p == '\\') { + if (inquotes) { +escape: + if (notescaped) + *q++ = '\\'; + } else { + /* naked back slash */ + notescaped = 0; + goto copy; + } with equivalent if (*p == (char)CTLESC) { p++; + goto escape; + } + if (*p == '\\') { + if (!inquotes) { + /* naked back slash */ + notescaped = 0; + goto copy; + } +escape: + if (notescaped) + *q++ = '\\'; -- To unsubscribe from this list: send the line "unsubscribe dash" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 2/21/18 2:50 PM, Denys Vlasenko wrote:
> I propose replacing this:
Agreed, that looks better. Thanks!
Cheers,
Harald van Dijk
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diff --git a/src/expand.c b/src/expand.c index 2a50830..af88a69 100644 --- a/src/expand.c +++ b/src/expand.c @@ -1686,12 +1686,17 @@ _rmescapes(char *str, int flag) } if (*p == (char)CTLESC) { p++; - if (notescaped) - *q++ = '\\'; - } else if (*p == '\\' && !inquotes) { - /* naked back slash */ - notescaped = 0; - goto copy; + goto escape; + } else if (*p == '\\') { + if (inquotes) { +escape: + if (notescaped) + *q++ = '\\'; + } else { + /* naked back slash */ + notescaped = 0; + goto copy; + } } notescaped = globbing; copy: diff --git a/src/parser.c b/src/parser.c index 382658e..a847b2e 100644 --- a/src/parser.c +++ b/src/parser.c @@ -909,7 +909,7 @@ readtoken1(int firstc, char const *syntax, char *eofmark, int striptabs) #endif CHECKEND(); /* set c to PEOF if at end of here document */ for (;;) { /* until end of line or end of word */ - CHECKSTRSPACE(4, out); /* permit 4 calls to USTPUTC */ + CHECKSTRSPACE(5, out); /* permit 5 calls to USTPUTC */ switch(syntax[c]) { case CNL: /* '\n' */ if (syntax == BASESYNTAX) @@ -944,6 +944,9 @@ readtoken1(int firstc, char const *syntax, char *eofmark, int striptabs) eofmark != NULL ) ) { + /* Reserve extra memory in case this backslash will require later escaping. */ + USTPUTC(CTLQUOTEMARK, out); + USTPUTC(CTLQUOTEMARK, out); USTPUTC('\\', out); } USTPUTC(CTLESC, out);