klibc - Jan 2019 - [klibc:update-dash] parser: Allow newlines within parameter substitution

Commit-ID:  5be21a4b26eb56c7d84544b30353920b35693614
Gitweb:    
http://git.kernel.org/?p=libs/klibc/klibc.git;a=commit;h=5be21a4b26eb56c7d84544b30353920b35693614
Author:     Herbert Xu <herbert at gondor.apana.org.au>
AuthorDate: Thu, 22 Mar 2018 21:41:24 +0800
Committer:  Ben Hutchings <ben at decadent.org.uk>
CommitDate: Fri, 25 Jan 2019 02:57:21 +0000

[klibc] parser: Allow newlines within parameter substitution

On Fri, Mar 16, 2018 at 11:27:22AM +0800, Herbert Xu
wrote:
> On Thu, Mar 15, 2018 at 10:49:15PM +0100, Harald van Dijk wrote:
> >
> > Okay, it can be trivially modified to something that does work in
other
> > shells (even if it were actually executed), but gets rejected at parse
time
> > by dash:
> >
> >   if false; then
> >     : ${$+
> >   }
> >   fi
>
> That's just a bug in dash's parser with ${} in general, because
> it bombs out without the if clause too:
>
> 	: ${$+
> 	}
This patch fixes the parsing of newlines with parameter substitution.

Signed-off-by: Herbert Xu <herbert at gondor.apana.org.au>
Signed-off-by: Ben Hutchings <ben at decadent.org.uk>

---
 usr/dash/parser.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/usr/dash/parser.c b/usr/dash/parser.c
index ae76400e..6a8a4a43 100644
--- a/usr/dash/parser.c
+++ b/usr/dash/parser.c
@@ -924,7 +924,8 @@ readtoken1(int firstc, char const *syntax, char *eofmark,
int striptabs)
 			CHECKSTRSPACE(4, out);	/* permit 4 calls to USTPUTC */
 			switch(synstack->syntax[c]) {
 			case CNL:	/* '\n' */
-				if (synstack->syntax == BASESYNTAX)
+				if (synstack->syntax == BASESYNTAX &&
+				    !synstack->varnest)
 					goto endword;	/* exit outer loop */
 				USTPUTC(c, out);
 				nlprompt();