sh: Add case statement fallthrough (with ';&' instead of ';;').

Replacing ;; with the new control operator ;& will cause the next list to be
executed as well without checking its pattern, continuing until a list ends
with ;; or until the end of the case statement. This is like omitting
"break" in a C "switch" statement.

The sequence ;& was formerly invalid.

This feature is proposed for the next POSIX issue in Austin Group issue
#449.

1 files changed, 8 insertions, 0 deletions

diff --git a/bin/sh/eval.c b/bin/sh/eval.c
index 25793c1..a22d4b1 100644
--- a/bin/sh/eval.c
+++ b/bin/sh/eval.c
@@ -386,6 +386,14 @@ evalcase(union node *n, int flags)
 	for (cp = n->ncase.cases ; cp && evalskip == 0 ; cp = cp->nclist.next) {
 		for (patp = cp->nclist.pattern ; patp ; patp = patp->narg.next) {
 			if (casematch(patp, arglist.list->text)) {
+				while (cp->nclist.next &&
+				    cp->type == NCLISTFALLTHRU) {
+					if (evalskip != 0)
+						break;
+					evaltree(cp->nclist.body,
+					    flags & ~EV_EXIT);
+					cp = cp->nclist.next;
+				}
 				if (evalskip == 0) {
 					evaltree(cp->nclist.body, flags);
 				}