diff --git a/mysql-test/r/type_float.result b/mysql-test/r/type_float.result
index f41c2e7688b..f498b6889a5 100644
--- a/mysql-test/r/type_float.result
+++ b/mysql-test/r/type_float.result
@@ -447,3 +447,21 @@ End of 5.0 tests
 select format(truncate('1.7976931348623157E+308',-12),1,'fr_BE') as foo;
 foo
 0
+#
+# Bug #13500371 63704: CONVERSION OF '1.' TO A NUMBER GIVES ERROR 1265
+# (WARN_DATA_TRUNCATED)
+#
+CREATE TABLE t1 (f FLOAT);
+INSERT INTO t1 VALUES ('1.');
+INSERT INTO t1 VALUES ('2.0.');
+Warnings:
+Warning	1265	Data truncated for column 'f' at row 1
+INSERT INTO t1 VALUES ('.');
+Warnings:
+Warning	1265	Data truncated for column 'f' at row 1
+SELECT * FROM t1 ORDER BY f;
+f
+0
+1
+2
+DROP TABLE t1;
diff --git a/mysql-test/t/type_float.test b/mysql-test/t/type_float.test
index b33c51566a0..96ce1bcbd9e 100644
--- a/mysql-test/t/type_float.test
+++ b/mysql-test/t/type_float.test
@@ -331,3 +331,15 @@ eval select concat((truncate((-1.7976931348623157E+307),(0x1e))),
 --echo #
 
 select format(truncate('1.7976931348623157E+308',-12),1,'fr_BE') as foo;
+
+--echo #
+--echo # Bug #13500371 63704: CONVERSION OF '1.' TO A NUMBER GIVES ERROR 1265
+--echo # (WARN_DATA_TRUNCATED)
+--echo #
+
+CREATE TABLE t1 (f FLOAT);
+INSERT INTO t1 VALUES ('1.');
+INSERT INTO t1 VALUES ('2.0.');
+INSERT INTO t1 VALUES ('.');
+SELECT * FROM t1 ORDER BY f;
+DROP TABLE t1;
diff --git a/strings/dtoa.c b/strings/dtoa.c
index f3498a7bb1e..c3ab347f94c 100644
--- a/strings/dtoa.c
+++ b/strings/dtoa.c
@@ -1410,7 +1410,7 @@ static double my_strtod_int(const char *s00, char **se, int *error, char *buf, s
     else if (nd < 16)
       z= 10*z + c - '0';
   nd0= nd;
-  if (s < end - 1 && c == '.')
+  if (s < end && c == '.')
   {
     ++s;
     if (!nd)