diff --git a/CHANGES b/CHANGES
index 77d5a75b31..b01ed0d236 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,7 @@
+4070.	[bug]		Fix a segfault in nslookup in a query such as
+			"nslookup isc.org AMS.SNS-PB.ISC.ORG -all".
+			[RT #38548]
+
 4069.	[doc]		Reorganize options in the nsupdate man page.
                         [RT #38516]
 
diff --git a/bin/dig/dighost.c b/bin/dig/dighost.c
index 3fa519a1dd..d317a3a7a3 100644
--- a/bin/dig/dighost.c
+++ b/bin/dig/dighost.c
@@ -3924,10 +3924,14 @@ isc_result_t
 get_address(char *host, in_port_t myport, isc_sockaddr_t *sockaddr) {
 	int count;
 	isc_result_t result;
+	isc_boolean_t is_running;
 
-	isc_app_block();
+	is_running = isc_app_isrunning();
+	if (is_running)
+		isc_app_block();
 	result = bind9_getaddresses(host, myport, sockaddr, 1, &count);
-	isc_app_unblock();
+	if (is_running)
+		isc_app_unblock();
 	if (result != ISC_R_SUCCESS)
 		return (result);
 
diff --git a/bin/dig/nslookup.c b/bin/dig/nslookup.c
index d3237fa5dc..30591dc556 100644
--- a/bin/dig/nslookup.c
+++ b/bin/dig/nslookup.c
@@ -585,7 +585,7 @@ version(void) {
 
 static void
 setoption(char *opt) {
-	if (strncasecmp(opt, "all", 4) == 0) {
+	if (strncasecmp(opt, "all", 3) == 0) {
 		show_settings(ISC_TRUE, ISC_FALSE);
 	} else if (strncasecmp(opt, "class=", 6) == 0) {
 		if (testclass(&opt[6]))
diff --git a/lib/isc/app_api.c b/lib/isc/app_api.c
index 46b9128f5d..a85d0b80c5 100644
--- a/lib/isc/app_api.c
+++ b/lib/isc/app_api.c
@@ -29,6 +29,7 @@
 static isc_mutex_t createlock;
 static isc_once_t once = ISC_ONCE_INIT;
 static isc_appctxcreatefunc_t appctx_createfunc = NULL;
+static isc_boolean_t is_running = ISC_FALSE;
 
 #define ISCAPI_APPMETHODS_VALID(m) ISC_MAGIC_VALID(m, ISCAPI_APPMETHODS_MAGIC)
 
@@ -198,12 +199,24 @@ isc_app_onrun(isc_mem_t *mctx, isc_task_t *task,
 
 isc_result_t
 isc_app_run() {
-	if (isc_bind9)
-		return (isc__app_run());
+	if (isc_bind9) {
+		isc_result_t result;
+
+		is_running = ISC_TRUE;
+		result = isc__app_run();
+		is_running = ISC_FALSE;
+
+		return (result);
+	}
 
 	return (ISC_R_NOTIMPLEMENTED);
 }
 
+isc_boolean_t
+isc_app_isrunning() {
+        return (is_running);
+}
+
 isc_result_t
 isc_app_shutdown(void) {
 	if (isc_bind9)
diff --git a/lib/isc/include/isc/app.h b/lib/isc/include/isc/app.h
index baefb82c2d..477b5eae2f 100644
--- a/lib/isc/include/isc/app.h
+++ b/lib/isc/include/isc/app.h
@@ -203,6 +203,16 @@ isc_app_run(void);
  *\li	ISC_R_RELOAD			Reload has been requested.
  */
 
+isc_boolean_t
+isc_app_isrunning(void);
+/*!<
+ * \brief Return if the ISC library application is running.
+ *
+ * Returns:
+ *\li	ISC_TRUE    App is running.
+ *\li	ISC_FALSE   App is not running.
+ */
+
 isc_result_t
 isc_app_ctxshutdown(isc_appctx_t *ctx);
 
diff --git a/lib/isc/win32/libisc.def.in b/lib/isc/win32/libisc.def.in
index 708dc3118a..ea6990551c 100644
--- a/lib/isc/win32/libisc.def.in
+++ b/lib/isc/win32/libisc.def.in
@@ -120,6 +120,7 @@ isc_app_ctxshutdown
 isc_app_ctxstart
 isc_app_ctxsuspend
 isc_app_finish
+isc_app_isrunning
 isc_app_onrun
 isc_app_register
 isc_app_reload