1 files changed, 18 insertions, 2 deletions
diff --git a/test/Sema/format-strings.c b/test/Sema/format-strings.c
index 6da027e..e31644a 100644
--- a/test/Sema/format-strings.c
+++ b/test/Sema/format-strings.c
@@ -1,8 +1,9 @@
 // RUN: %clang_cc1 -fsyntax-only -verify -Wformat-nonliteral -isystem %S/Inputs %s
 // RUN: %clang_cc1 -fsyntax-only -verify -Wformat-nonliteral -isystem %S/Inputs -fno-signed-char %s
 
-#define __need_wint_t
 #include <stdarg.h>
+#include <stddef.h>
+#define __need_wint_t
 #include <stddef.h> // For wint_t and wchar_t
 
 typedef struct _FILE FILE;
@@ -535,6 +536,21 @@ void pr9751() {
          0.0); // expected-warning{{format specifies}}
 }
 
+void pr18905() {
+  const char s1[] = "s\0%s"; // expected-note{{format string is defined here}}
+  const char s2[1] = "s"; // expected-note{{format string is defined here}}
+  const char s3[2] = "s\0%s"; // expected-warning{{initializer-string for char array is too long}}
+  const char s4[10] = "s";
+  const char s5[0] = "%s"; // expected-warning{{initializer-string for char array is too long}}
+                           // expected-note@-1{{format string is defined here}}
+
+  printf(s1); // expected-warning{{format string contains '\0' within the string body}}
+  printf(s2); // expected-warning{{format string is not null-terminated}}
+  printf(s3); // no-warning
+  printf(s4); // no-warning
+  printf(s5); // expected-warning{{format string is not null-terminated}}
+}
+
 void __attribute__((format(strfmon,1,2))) monformat(const char *fmt, ...);
 void __attribute__((format(strftime,1,0))) dateformat(const char *fmt);
 
@@ -544,7 +560,7 @@ void test_other_formats() {
   monformat("", 1); // expected-warning{{format string is empty}}
   monformat(str); // expected-warning{{format string is not a string literal (potentially insecure)}}
   dateformat(""); // expected-warning{{format string is empty}}
-  dateformat(str); // no-warning (using strftime non literal is not unsafe)
+  dateformat(str); // no-warning (using strftime non-literal is not unsafe)
 }
 
 // Do not warn about unused arguments coming from system headers.