Index: lib/sanitizer_common/sanitizer_common_interceptors.inc
===================================================================
--- lib/sanitizer_common/sanitizer_common_interceptors.inc
+++ lib/sanitizer_common/sanitizer_common_interceptors.inc
@@ -307,7 +307,7 @@
 INTERCEPTOR(char*, textdomain, const char *domainname) {
   void *ctx;
   COMMON_INTERCEPTOR_ENTER(ctx, textdomain, domainname);
-  COMMON_INTERCEPTOR_READ_STRING(ctx, domainname, 0);
+  if (domainname) COMMON_INTERCEPTOR_READ_STRING(ctx, domainname, 0);
   char *domain = REAL(textdomain)(domainname);
   if (domain) {
     COMMON_INTERCEPTOR_INITIALIZE_RANGE(domain, REAL(strlen)(domain) + 1);
Index: test/asan/TestCases/textdomain.c
===================================================================
--- /dev/null
+++ test/asan/TestCases/textdomain.c
@@ -0,0 +1,10 @@
+// RUN: %clang_asan -O0 -g %s -o %t
+// RUN: %env_asan_opts=strict_string_checks=1 %run %t
+
+#include <stdlib.h>
+#include <libintl.h>
+
+int main() {
+  textdomain(NULL);
+  return 0;
+}