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ash: [PARSER] Handle backslash newlines properly after dollar sign

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Fixes var_unbackslash1.tests failure.

Upstream commit:

    [PARSER] Handle backslash newlines properly after dollar sign

    On Tue, Aug 26, 2014 at 12:34:42PM +0000, Eric Blake wrote:
    > On 08/26/2014 06:15 AM, Oleg Bulatov wrote:
    > > While playing with sh generators I found that dash and bash have different
    > > interpretations for <slash><newline> sequence.
    > >
    > > $ dash -c 'EDIT=xxx; echo $EDIT\
    > >> OR'
    > > xxxOR
    >
    > Buggy.
    > >
    > > $ dash -c 'echo "$\
    > > (pwd)"'
    > > $(pwd)
    > >
    > > Is it undefined behaviour in POSIX?
    >
    > No, it's well-defined, and dash is buggy.
    ...

    I agree.  This patch should resolve this problem and similar ones
    affecting blackslash newlines after we encounter a dollar sign.

    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2016-09-29 17:17:04 +02:00
parent 8286513838
commit 73c3e074df
1 changed files with 29 additions and 15 deletions
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44
shell/ash.c
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@ -9774,11 +9774,6 @@ popstring(void)
INT_ON;
}
//FIXME: BASH_COMPAT with "...&" does TWO pungetc():
//it peeks whether it is &>, and then pushes back both chars.
//This function needs to save last *next_to_pgetc to buf[0]
//to make two pungetc() reliable. Currently,
// pgetc (out of buf: does preadfd), pgetc, pungetc, pungetc won't work...
static int
preadfd(void)
{
@ -10037,6 +10032,25 @@ pungetc(void)
g_parsefile->unget++;
}
/* This one eats backslash+newline */
static int
pgetc_eatbnl(void)
{
int c;
while ((c = pgetc()) == '\\') {
if (pgetc() != '\n') {
pungetc();
break;
}
g_parsefile->linno++;
setprompt_if(doprompt, 2);
}
return c;
}
/*
* To handle the "." command, a stack of input files is used. Pushfile
* adds a new entry to the stack and popfile restores the previous level.
@ -11625,7 +11639,7 @@ parsesub: {
int typeloc;
int flags;
c = pgetc();
c = pgetc_eatbnl();
if (c > 255 /* PEOA or PEOF */
|| (c != '(' && c != '{' && !is_name(c) && !is_special(c))
) {
@ -11638,7 +11652,7 @@ parsesub: {
pungetc();
} else if (c == '(') {
/* $(command) or $((arith)) */
if (pgetc() == '(') {
if (pgetc_eatbnl() == '(') {
#if ENABLE_SH_MATH_SUPPORT
PARSEARITH();
#else
@ -11655,9 +11669,9 @@ parsesub: {
USTPUTC(VSNORMAL, out);
subtype = VSNORMAL;
if (c == '{') {
c = pgetc();
c = pgetc_eatbnl();
if (c == '#') {
c = pgetc();
c = pgetc_eatbnl();
if (c == '}')
c = '#'; /* ${#} - same as $# */
else
@ -11670,18 +11684,18 @@ parsesub: {
/* $[{[#]]NAME[}] */
do {
STPUTC(c, out);
c = pgetc();
c = pgetc_eatbnl();
} while (c <= 255 /* not PEOA or PEOF */ && is_in_name(c));
} else if (isdigit(c)) {
/* $[{[#]]NUM[}] */
do {
STPUTC(c, out);
c = pgetc();
c = pgetc_eatbnl();
} while (isdigit(c));
} else if (is_special(c)) {
/* $[{[#]]<specialchar>[}] */
USTPUTC(c, out);
c = pgetc();
c = pgetc_eatbnl();
} else {
badsub:
raise_error_syntax("bad substitution");
@ -11699,7 +11713,7 @@ parsesub: {
/* c == first char after VAR */
switch (c) {
case ':':
c = pgetc();
c = pgetc_eatbnl();
#if ENABLE_ASH_BASH_COMPAT
/* This check is only needed to not misinterpret
* ${VAR:-WORD}, ${VAR:+WORD}, ${VAR:=WORD}, ${VAR:?WORD}
@ -11724,7 +11738,7 @@ parsesub: {
case '#': {
int cc = c;
subtype = (c == '#' ? VSTRIMLEFT : VSTRIMRIGHT);
c = pgetc();
c = pgetc_eatbnl();
if (c != cc)
goto do_pungetc;
subtype++;
@ -11736,7 +11750,7 @@ parsesub: {
//TODO: encode pattern and repl separately.
// Currently ${v/$var_with_slash/repl} is horribly broken
subtype = VSREPLACE;
c = pgetc();
c = pgetc_eatbnl();
if (c != '/')
goto do_pungetc;
subtype++; /* VSREPLACEALL */