expression: Fix the bug that castStringAsReal has different behaivor …

…between tiflash and tikv/tidb. (#3681) (#3757) ref #3447, close #3475
pingcap · Jun 17, 2022 · c1a9569 · c1a9569
1 parent 3b3e86c
commit c1a9569
Show file tree

Hide file tree

Showing 3 changed files with 11 additions and 4 deletions.
diff --git a/dbms/src/Functions/FunctionsTiDBConversion.h b/dbms/src/Functions/FunctionsTiDBConversion.h
@@ -680,6 +680,8 @@ struct TiDBConvertToFloat
             context.getDAGContext()->handleTruncateError("Truncated incorrect DOUBLE value");
             return 0.0;
         }
+        if (float_string.size < trim_string.size())
+            trim_string[float_string.size] = '\0';
         Float64 f = strtod(float_string.data, nullptr);
         if (f == std::numeric_limits<Float64>::infinity())
         {

diff --git a/tests/fullstack-test/expr/cast_string_as_real.test b/tests/fullstack-test/expr/cast_string_as_real.test
@@ -1,29 +1,35 @@
 mysql> drop table if exists test.t
 mysql> create table test.t(a char(30))
 mysql> alter table test.t set tiflash replica 1
-mysql> insert into test.t values ('1.23'),('123'),('-123.99'),('+123.123-'),(0),(0.0),(NULL),('1.11.00'),('11xx'),('11.xx'),('xx.11'),('1e649'),('-1e649'),('9.9999999999999999'),('9.999999999999999')
+mysql> insert into test.t values ('1.23'),('123'),('-123.99'),('+123.123-'),(0),(0.0),(NULL),('1.11.00'),('11xx'),('11.xx'),('xx.11'),('1e649'),('-1e649'),('9.9999999999999999'),('9.999999999999999');
+mysql> insert into test.t values ('0x01'),('-0x01'),('1x01'),('-1x01.2'),('0x01.2'),('x1');
 
 func> wait_table test t
 
-mysql> set tidb_allow_mpp=1; set tidb_isolation_read_engines='tiflash'; select a, b from (select a, cast(a as double) as b from test.t) t group by a, b order by a
+mysql> set tidb_enforce_mpp=1; set tidb_isolation_read_engines='tiflash'; select a, cast(a as double) b from test.t order by a;
 +--------------------+-------------------------+
 | a                  | b                       |
 +--------------------+-------------------------+
 | NULL               |                    NULL |
 | +123.123-          |                 123.123 |
+| -0x01              |                      -0 |
 | -123.99            |                 -123.99 |
 | -1e649             | -1.7976931348623157e308 |
+| -1x01.2            |                      -1 |
 | 0                  |                       0 |
 | 0.0                |                       0 |
+| 0x01               |                       0 |
+| 0x01.2             |                       0 |
 | 1.11.00            |                    1.11 |
 | 1.23               |                    1.23 |
 | 11.xx              |                      11 |
 | 11xx               |                      11 |
 | 123                |                     123 |
 | 1e649              |  1.7976931348623157e308 |
+| 1x01               |                       1 |
 | 9.999999999999999  |       9.999999999999998 |
 | 9.9999999999999999 |                      10 |
+| x1                 |                       0 |
 | xx.11              |                       0 |
 +--------------------+-------------------------+
 
-mysql> drop table if exists test.t
diff --git a/tests/fullstack-test/expr/issue_3447.test b/tests/fullstack-test/expr/issue_3447.test
@@ -11,5 +11,4 @@ mysql> select /*+ read_from_storage(tiflash[t]) */ * from test.t where a;
 | 0.1  |
 | -0.1 |
 | -1   |
-| 0x01 |
 +------+
-Original file line number
+Diff line change
@@ Expand Up @@
     | 0.1  |
     | -0.1 |
     | -1   |
-    | 0x01 |
     +------+