shells: testcase: add another test for EINTR on fifo open

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

shell/ash_test/ash-redir/redir_EINTR2.right

@@ -0,0 +1,2 @@
+Hello
+Done:0

shell/ash_test/ash-redir/redir_EINTR2.tests

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+rm -f test.fifo
+mkfifo test.fifo
+
+(sleep 1; kill -chld $$) &
+(sleep 2; echo Hello >test.fifo) &
+
+# We get open("test.fifo") interrupted by SIGCHLD from the first subshell.
+# The shell MUST retry the open (no printing of error messages).
+# Then, the second subshell opens fifo for writing and open unblocks and succeeds.
+read HELLO <test.fifo
+echo "$HELLO"
+
+echo "Done:$?"
+rm -f test.fifo

shell/hush_test/hush-redir/redir_EINTR2.right

@@ -0,0 +1,2 @@
+Hello
+Done:0

shell/hush_test/hush-redir/redir_EINTR2.tests

@@ -0,0 +1,14 @@
+rm -f test.fifo
+mkfifo test.fifo
+
+(sleep 1; kill -chld $$) &
+(sleep 2; echo Hello >test.fifo) &
+
+# We get open("test.fifo") interrupted by SIGCHLD from the first subshell.
+# The shell MUST retry the open (no printing of error messages).
+# Then, the second subshell opens fifo for writing and open unblocks and succeeds.
+read HELLO <test.fifo
+echo "$HELLO"
+
+echo "Done:$?"
+rm -f test.fifo