-# Check that "ulimit" itself works.
-((ulimit -n 100 &&
- tar -cf archive1.tar a 3<&- 4<&- 5<&- 6<&- 7<&- 8<&- 9<&- &&
- tar -xf archive1.tar -C dest1 a 3<&- 4<&- 5<&- 6<&- 7<&- 8<&- 9<&-
- ) &&
- diff -r a dest1/a
+# Check that "ulimit" itself works. Close file descriptors before
+# invoking ulimit, to work around a bug (or a "feature") in some shells,
+# where they squirrel away dups of file descriptors into FD 10 and up
+# before closing the originals.
+( (exec 3<&- 4<&- 5<&- 6<&- 7<&- 8<&- 9<&- &&
+ ulimit -n 100 &&
+ tar -cf archive1.tar a &&
+ tar -xf archive1.tar -C dest1 a
+ ) &&
+ diff -r a dest1/a