testsuite: Test for #13786

testsuite/tests/ghci/T13786/Makefile

+TOP=../../..
+include $(TOP)/mk/boilerplate.mk
+include $(TOP)/mk/test.mk
+
+.PHONY: T13786
+T13786 :
+	"$(TEST_HC)" $(TEST_HC_OPTS) -v0 -c -fPIC T13786a.c
+	"$(TEST_HC)" $(TEST_HC_OPTS) -v0 -c -fPIC T13786b.c
+	cat T13786.script | "$(TEST_HC)" $(TEST_HC_OPTS_INTERACTIVE) -v0 T13786a.o T13786b.o T13786.hs

testsuite/tests/ghci/T13786/T13786.hs

+{-# LANGUAGE ForeignFunctionInterface #-}
+
+foreign import ccall unsafe "hello_a" helloA :: IO ()
+

testsuite/tests/ghci/T13786/T13786.script

+helloA

testsuite/tests/ghci/T13786/T13786.stdout

+hello world A
+hello world B
+hello world A
+

testsuite/tests/ghci/T13786/T13786a.c

+#include <stdio.h>
+#include <stdbool.h>
+
+static bool flag_a = false;
+
+extern void hello_b();
+
+void hello_a() {
+  if (! flag_a) {
+      flag_a = true;
+      hello_b();
+  }
+
+  printf("hello world A\n");
+}

testsuite/tests/ghci/T13786/T13786b.c

+#include <stdio.h>
+#include <stdbool.h>
+
+static bool flag_b = false;
+
+extern void hello_a();
+
+void hello_b() {
+  if (! flag_b) {
+      flag_b = true;
+      hello_a();
+  }
+
+  printf("hello world B\n");
+}
+

testsuite/tests/ghci/T13786/all.T

+test('T13786', normal, makefile_test, [])
+