chmod: bug handling comma after right hand ugo.

* sysif.c (chmod_wrap): The chm_comma state is transitioned to
after seeing a right hand side u, g or o. These do not combine
with other letters, so ch_comma expects a comma after which a
new permission clause we start,.  Therefore the srcm and who
variables must be rest.  It's also a good idea to continue the
loop.

* tests/018/chmod.tl: New test case which exposed
the above issue.

2 files changed, 2 insertions, 2 deletions

diff --git a/sysif.c b/sysif.c
index 44e236d7..8778a242 100644
--- a/sysif.c
+++ b/sysif.c
@@ -630,8 +630,7 @@ static val chmod_wrap(val target, val mode)
         case chm_comma:
           if (ch != ',')
             goto inval;
-          cs = chm_who;
-          break;
+          srcm = 0; who = 0; cs = chm_who; continue;
         }
 
         {
diff --git a/tests/018/chmod.tl b/tests/018/chmod.tl
index f815548c..a5494998 100644
--- a/tests/018/chmod.tl
+++ b/tests/018/chmod.tl
@@ -40,3 +40,4 @@
 (cht "------------" "+rwx,g-r+w,o-r+w"  "---rwx-wx-wx")
 (cht "---------rwx" "u=rwsx"            "s--rwx---rwx")
 (cht "---------rwx" "u=rwsx,g=rwx,go-x" "s--rwxrw-rw-")
+(cht "---------rwx" "g=o,g-w+s,u=g,o-x" "-g-r-xr-xrw-")