[PATCH] xargs: fix handling of quoted arguments, closes 11441

[Ron Yorston]

As reported in bug 11441 when presented with a large number of quoted
arguments xargs can return 'argument line too long':

   seq 10000 29999 | sed -e 's/^/"/' -e 's/$/"/' | busybox xargs echo

This happens because the variant of process_stdin() which handles quoted
arguments doesn't preserve state between calls.  If the allowed number
of characters is exceeded part way through a quoted argument the next
call to process_stdin() incorrectly treats the terminating quote as a
starting quote, thus quoting all of the argument separators.

function                                             old     new   delta
process_stdin                                        301     314     +13
static.state                                           -       1      +1
static.q                                               -       1      +1
------------------------------------------------------------------------------
(add/remove: 2/0 grow/shrink: 1/0 up/down: 15/0)               Total: 15 bytes

Signed-off-by: Ron Yorston <rmy at pobox.com>
---
 findutils/xargs.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/findutils/xargs.c b/findutils/xargs.c
index 726315803..d215517af 100644
--- a/findutils/xargs.c
+++ b/findutils/xargs.c
@@ -261,8 +261,8 @@ static char* FAST_FUNC process_stdin(int n_max_chars, int n_max_arg, char *buf)
 #define QUOTE     1
 #define BACKSLASH 2
 #define SPACE     4
-	char q = '\0';             /* quote char */
-	char state = NORM;
+	static char q = '\0';             /* quote char */
+	static char state = NORM;
 	char *s = buf;             /* start of the word */
 	char *p = s + strlen(buf); /* end of the word */
 
-- 
2.24.1