Add a couple of regression tests for dlerror() handling.

regress/usr.bin/rtld/Makefile

@@ -1,5 +1,5 @@
-# $NetBSD: Makefile,v 1.1 2000/12/08 19:24:29 drochner Exp $
+# $NetBSD: Makefile,v 1.2 2002/11/14 21:10:45 nathanw Exp $
 
-SUBDIR+= dlopen testlib
+SUBDIR+= dlopen testlib dlerror-false dlerror-cleared
 
 .include <bsd.subdir.mk>

regress/usr.bin/rtld/dlerror-cleared/Makefile

@@ -0,0 +1,10 @@
+# $NetBSD: Makefile,v 1.1 2002/11/14 21:10:46 nathanw Exp $
+
+NOMAN=	# defined
+
+PROG=	dlerror-cleared
+
+regress:
+	./${PROG}
+
+.include <bsd.prog.mk>

regress/usr.bin/rtld/dlerror-cleared/dlerror-cleared.c

@@ -0,0 +1,22 @@
+#include <stdio.h>
+#include <dlfcn.h>
+#include <err.h>
+
+int main(void)
+{
+	void *handle;
+	char *error;
+
+	/*
+	 * Test that an error set by dlopen() persists past a successful
+	 * dlopen() call.
+	 */
+	handle = dlopen("libnonexistent.so", DL_LAZY);
+	handle = dlopen("libm.so", DL_LAZY);
+	error = dlerror();
+	if (error == NULL)
+		errx(1, "Failed: dlerror() was cleared by successful dlopen()\n");
+	printf("OK: %s\n", error);
+	
+	return 0;
+}

regress/usr.bin/rtld/dlerror-false/Makefile

@@ -0,0 +1,12 @@
+# $NetBSD: Makefile,v 1.1 2002/11/14 21:10:47 nathanw Exp $
+
+NOMAN=	# defined
+
+PROG=	dlerror-false
+
+LDADD=	-Wl,-rpath,/var/nonexistent/lib
+
+regress:
+	./${PROG}
+
+.include <bsd.prog.mk>

regress/usr.bin/rtld/dlerror-false/dlerror-false.c

@@ -0,0 +1,38 @@
+#include <stdio.h>
+#include <dlfcn.h>
+#include <err.h>
+
+int main(void)
+{
+	void *handle, *sym;
+	char *error;
+
+	/*
+	 * Test for dlerror() being set by a successful library open.
+	 * Requires that the rpath be set to something that does not
+	 * include libm.so.
+	 */
+
+	handle = dlopen("libm.so", DL_LAZY);
+	error = dlerror();
+	if (error != NULL)
+		errx(1, "Error opening libm.so: %s", error);
+	if (handle == NULL)
+		errx(1, "Library handle is NULL but dlerror not set.");
+
+	sym = dlsym(handle, "sin");
+	error = dlerror();
+	if (error != NULL)
+		errx(1, "Error looking up sin(): %s", error);
+	if (sym == NULL)
+		errx(1, "Looked-up symbol is NULL but dlerror not set.");
+
+	dlclose(handle);
+	error = dlerror();
+	if (error != NULL)
+		errx(1, "Error calling dlclose(): %s", error);
+
+	printf("OK\n");
+
+	return 0;
+}