msvcrt: Fix _strnicmp and _strnicmp_l implementation.

dlls/msvcrt/string.c

@@ -3313,11 +3313,15 @@ int __cdecl _strnicmp_l(const char *s1, const char *s2,
     pthreadlocinfo locinfo;
     int c1, c2;
 
-    if(s1==NULL || s2==NULL)
-        return _NLSCMPERROR;
-
     if(!count)
         return 0;
+#if _MSVCR_VER>=80
+    if(!MSVCRT_CHECK_PMT(s1 && s2 && count <= INT_MAX))
+#else
+    /* Old versions of msvcrt.dll didn't have count <= INT_MAX check */
+    if(!MSVCRT_CHECK_PMT(s1 && s2))
+#endif /* _MSVCR_VER>=140 */
+        return _NLSCMPERROR;
 
     if(!locale)
         locinfo = get_locinfo();
@@ -3349,7 +3353,7 @@ int __cdecl _strnicmp_l(const char *s1, const char *s2,
  */
 int __cdecl _stricmp_l(const char *s1, const char *s2, _locale_t locale)
 {
-    return _strnicmp_l(s1, s2, -1, locale);
+    return _strnicmp_l(s1, s2, INT_MAX, locale);
 }
 
 /*********************************************************************
@@ -3365,7 +3369,7 @@ int __cdecl _strnicmp(const char *s1, const char *s2, size_t count)
  */
 int __cdecl _stricmp(const char *s1, const char *s2)
 {
-    return _strnicmp_l(s1, s2, -1, NULL);
+    return _strnicmp_l(s1, s2, INT_MAX, NULL);
 }
 
 /*********************************************************************

dlls/ucrtbase/tests/string.c

@@ -482,13 +482,31 @@ static void test__strnicmp(void)
 
     SET_EXPECT(invalid_parameter_handler);
     errno = 0xdeadbeef;
+    ret = _strnicmp(str1, NULL, 2);
+    CHECK_CALLED(invalid_parameter_handler);
+    ok(ret == _NLSCMPERROR, "got %d.\n", ret);
+    ok(errno == EINVAL, "Unexpected errno %d.\n", errno);
+
+    SET_EXPECT(invalid_parameter_handler);
+    errno = 0xdeadbeef;
     ret = _strnicmp(str1, str2, -1);
-    todo_wine CHECK_CALLED(invalid_parameter_handler);
-    todo_wine ok(ret == _NLSCMPERROR, "got %d.\n", ret);
-    todo_wine ok(errno == EINVAL, "Unexpected errno %d.\n", errno);
+    CHECK_CALLED(invalid_parameter_handler);
+    ok(ret == _NLSCMPERROR, "got %d.\n", ret);
+    ok(errno == EINVAL, "Unexpected errno %d.\n", errno);
+
+    ret = _strnicmp(str1, str2, 0);
+    ok(!ret, "got %d.\n", ret);
 
     ret = _strnicmp(str1, str2, 0x7fffffff);
     ok(!ret, "got %d.\n", ret);
+
+    /* If numbers of characters to compare is too big return error */
+    SET_EXPECT(invalid_parameter_handler);
+    errno = 0xdeadbeef;
+    ret = _strnicmp(str1, str2, 0x80000000);
+    CHECK_CALLED(invalid_parameter_handler);
+    ok(ret == _NLSCMPERROR, "got %d.\n", ret);
+    ok(errno == EINVAL, "Unexpected errno %d.\n", errno);
 }
 
 static void test_wcsnicmp(void)