[PATCH 14/18] conf: Rework checking for garbage after a range

[David Gibson <david@gibson.dropbear.id.au>]

After parsing port ranges conf_ports_spec() checks if we've reached a
chunk delimiter (',') to verify that there isn't extra garbage there.
Rework how we do this to use the recently introduces chunk-end pointer.
This has two advantages:

1) Small, but practical: we don't need to repeat what the valid delimiters
   are, that's already handled in the chunk splitting code.

2) Large, if theoretical: this will also given an error if port parsing
   overruns a chunk boundary.  We don't really expect that to happen, but
   it would give very confusing behaviour if it did.  strtoul(3), on which
   parse_port_range() is based does say it may accept thousands separators
   based on locale which means can't entirely be sure it will only accept
   strings of digits.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 conf.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/conf.c b/conf.c
index 1ab1b071..51612047 100644
--- a/conf.c
+++ b/conf.c
@@ -264,7 +264,7 @@ static void conf_ports_spec(const struct ctx *c,
 
 		if (parse_port_range(p, &p, &xrange))
 			goto bad;
-		if ((*p != '\0')  && (*p != ',')) /* Garbage after the range */
+		if (p != ep) /* Garbage after the range */
 			goto bad;
 
 		for (i = xrange.first; i <= xrange.last; i++)
@@ -303,7 +303,7 @@ static void conf_ports_spec(const struct ctx *c,
 			mapped_range = orig_range;
 		}
 
-		if ((*p != '\0')  && (*p != ',')) /* Garbage after the ranges */
+		if (p != ep) /* Garbage after the ranges */
 			goto bad;
 
 		if (orig_range.first == 0) {
-- 
2.53.0