sh: Check readonly status for assignments on regular builtins.

An error message is written, the builtin is not executed, nonzero exit
status is returned but the shell does not abort.

This was already checked for special builtins and external commands, with
the same consequences except that the shell aborts for special builtins.

Obtained from:	NetBSD

1 files changed, 6 insertions, 2 deletions

diff --git a/bin/sh/var.c b/bin/sh/var.c
index 6c0618f..e841647 100644
--- a/bin/sh/var.c
+++ b/bin/sh/var.c
@@ -333,6 +333,8 @@ setvareq(char *s, int flags)
 				len = strchr(s, '=') - s;
 				error("%.*s: is read only", len, s);
 			}
+			if (flags & VNOSET)
+				return;
 			INTOFF;
 
 			if (vp->func && (flags & VNOFUNC) == 0)
@@ -365,6 +367,8 @@ setvareq(char *s, int flags)
 		}
 	}
 	/* not found */
+	if (flags & VNOSET)
+		return;
 	vp = ckmalloc(sizeof (*vp));
 	vp->flags = flags;
 	vp->text = s;
@@ -386,13 +390,13 @@ setvareq(char *s, int flags)
  */
 
 void
-listsetvar(struct strlist *list)
+listsetvar(struct strlist *list, int flags)
 {
 	struct strlist *lp;
 
 	INTOFF;
 	for (lp = list ; lp ; lp = lp->next) {
-		setvareq(savestr(lp->text), 0);
+		setvareq(savestr(lp->text), flags);
 	}
 	INTON;
 }