MDEV-20303 SPACE(-1) returns a wrong data type

3 files changed, 158 insertions, 57 deletions

diff --git a/mysql-test/main/func_str.result b/mysql-test/main/func_str.result
index eb00837eaaf..2d86d384288 100644
--- a/mysql-test/main/func_str.result
+++ b/mysql-test/main/func_str.result
@@ -5073,16 +5073,84 @@ DROP TABLE t1;
 CREATE OR REPLACE TABLE t1 (i BIGINT);
 INSERT INTO t1 VALUES (42);
 CREATE OR REPLACE TABLE t2 AS SELECT
+REPEAT(i,NULL) AS cn,
 REPEAT(i,0) AS c0,
 REPEAT(i,-1) AS c1
 FROM t1;
 SHOW CREATE TABLE t2;
 Table	Create Table
 t2	CREATE TABLE `t2` (
+  `cn` char(0) CHARACTER SET utf8 DEFAULT NULL,
   `c0` char(0) CHARACTER SET utf8 DEFAULT NULL,
   `c1` char(0) CHARACTER SET utf8 DEFAULT NULL
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 DROP TABLE t1, t2;
 #
+# MDEV-20303 SPACE(-1) returns a wrong data type
+#
+CREATE TABLE t1 (i BIGINT);
+INSERT INTO t1 VALUES (42);
+CREATE TABLE t2 AS SELECT
+SPACE(NULL) AS cn,
+SPACE(0) AS c0,
+SPACE(-1) AS c1
+FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `cn` char(0) CHARACTER SET utf8 DEFAULT NULL,
+  `c0` char(0) CHARACTER SET utf8 DEFAULT NULL,
+  `c1` char(0) CHARACTER SET utf8 DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t1, t2;
+CREATE TABLE t1 (i BIGINT);
+INSERT INTO t1 VALUES (42);
+CREATE TABLE t2 AS SELECT
+LPAD(i,NULL,'a') AS cn,
+LPAD(i,0,'a') AS c0,
+LPAD(i,-1,'a') AS c1
+FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `cn` char(0) CHARACTER SET utf8 DEFAULT NULL,
+  `c0` char(0) CHARACTER SET utf8 DEFAULT NULL,
+  `c1` char(0) CHARACTER SET utf8 DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t1, t2;
+CREATE TABLE t1 (i BIGINT);
+INSERT INTO t1 VALUES (42);
+CREATE TABLE t2 AS SELECT
+RPAD(i,NULL,'a') AS cn,
+RPAD(i,0,'a') AS c0,
+RPAD(i,-1,'a') AS c1
+FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `cn` char(0) CHARACTER SET utf8 DEFAULT NULL,
+  `c0` char(0) CHARACTER SET utf8 DEFAULT NULL,
+  `c1` char(0) CHARACTER SET utf8 DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t1, t2;
+CREATE TABLE t1 (i BIGINT);
+INSERT INTO t1 VALUES (42);
+CREATE TABLE t2 AS SELECT
+LEFT(i,NULL) AS cn,
+LEFT(i,0) AS c0,
+LEFT(i,18446744073709551615) AS c1
+FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `cn` char(0) CHARACTER SET utf8 DEFAULT NULL,
+  `c0` char(0) CHARACTER SET utf8 DEFAULT NULL,
+  `c1` varchar(20) CHARACTER SET utf8 DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+SELECT c1 FROM t2;
+c1
+42
+DROP TABLE t1, t2;
+#
 # End of 10.3 tests
 #
diff --git a/mysql-test/main/func_str.test b/mysql-test/main/func_str.test
index 135d00bcd8c..60a142cda20 100644
--- a/mysql-test/main/func_str.test
+++ b/mysql-test/main/func_str.test
@@ -2035,6 +2035,7 @@ DROP TABLE t1;
 CREATE OR REPLACE TABLE t1 (i BIGINT);
 INSERT INTO t1 VALUES (42);
 CREATE OR REPLACE TABLE t2 AS SELECT
+  REPEAT(i,NULL) AS cn,
   REPEAT(i,0) AS c0,
   REPEAT(i,-1) AS c1
 FROM t1;
@@ -2043,5 +2044,51 @@ DROP TABLE t1, t2;
 
 
 --echo #
+--echo # MDEV-20303 SPACE(-1) returns a wrong data type
+--echo #
+
+CREATE TABLE t1 (i BIGINT);
+INSERT INTO t1 VALUES (42);
+CREATE TABLE t2 AS SELECT
+  SPACE(NULL) AS cn,
+  SPACE(0) AS c0,
+  SPACE(-1) AS c1
+FROM t1;
+SHOW CREATE TABLE t2;
+DROP TABLE t1, t2;
+
+CREATE TABLE t1 (i BIGINT);
+INSERT INTO t1 VALUES (42);
+CREATE TABLE t2 AS SELECT
+  LPAD(i,NULL,'a') AS cn,
+  LPAD(i,0,'a') AS c0,
+  LPAD(i,-1,'a') AS c1
+FROM t1;
+SHOW CREATE TABLE t2;
+DROP TABLE t1, t2;
+
+CREATE TABLE t1 (i BIGINT);
+INSERT INTO t1 VALUES (42);
+CREATE TABLE t2 AS SELECT
+  RPAD(i,NULL,'a') AS cn,
+  RPAD(i,0,'a') AS c0,
+  RPAD(i,-1,'a') AS c1
+FROM t1;
+SHOW CREATE TABLE t2;
+DROP TABLE t1, t2;
+
+CREATE TABLE t1 (i BIGINT);
+INSERT INTO t1 VALUES (42);
+CREATE TABLE t2 AS SELECT
+  LEFT(i,NULL) AS cn,
+  LEFT(i,0) AS c0,
+  LEFT(i,18446744073709551615) AS c1
+FROM t1;
+SHOW CREATE TABLE t2;
+SELECT c1 FROM t2;
+DROP TABLE t1, t2;
+
+
+--echo #
 --echo # End of 10.3 tests
 --echo #
diff --git a/sql/item_strfunc.cc b/sql/item_strfunc.cc
index 65acc071237..b170634d864 100644
--- a/sql/item_strfunc.cc
+++ b/sql/item_strfunc.cc
@@ -58,6 +58,27 @@ C_MODE_END
 
 size_t username_char_length= 80;
 
+
+class Repeat_count
+{
+  ulonglong m_count;
+public:
+  Repeat_count(Item *item)
+   :m_count(0)
+  {
+    Longlong_hybrid nr= item->to_longlong_hybrid();
+    if (!item->null_value && !nr.neg())
+    {
+      // Assume that the maximum length of a String is < INT_MAX32
+      m_count= (ulonglong) nr.value();
+      if (m_count > (ulonglong) INT_MAX32)
+        m_count= (ulonglong) INT_MAX32;
+    }
+  }
+  ulonglong count() const { return m_count; }
+};
+
+
 /*
   For the Items which have only val_str_ascii() method
   and don't have their own "native" val_str(),
@@ -1635,13 +1656,10 @@ String *Item_func_left::val_str(String *str)
 void Item_str_func::left_right_max_length()
 {
   uint32 char_length= args[0]->max_char_length();
-  if (args[1]->const_item())
+  if (args[1]->const_item() && !args[1]->is_expensive())
   {
-    int length= (int) args[1]->val_int();
-    if (args[1]->null_value || length <= 0)
-      char_length=0;
-    else
-      set_if_smaller(char_length, (uint) length);
+    Repeat_count tmp(args[1]);
+    set_if_smaller(char_length, (uint) tmp.count());
   }
   fix_char_length(char_length);
 }
@@ -2969,25 +2987,14 @@ bool Item_func_repeat::fix_length_and_dec()
   DBUG_ASSERT(collation.collation != NULL);
   if (args[1]->const_item() && !args[1]->is_expensive())
   {
-    Longlong_hybrid nr= args[1]->to_longlong_hybrid();
-    if (args[1]->null_value || nr.neg())
-      fix_char_length(0);
-    else
-    {
-      /* Assumes that the maximum length of a String is < INT_MAX32. */
-      longlong count= nr.value();
-      if (count > INT_MAX32)
-        count= INT_MAX32;
-      ulonglong char_length= (ulonglong) args[0]->max_char_length() * count;
-      fix_char_length_ulonglong(char_length);
-    }
-  }
-  else
-  {
-    max_length= MAX_BLOB_WIDTH;
-    maybe_null= 1;
+    Repeat_count tmp(args[1]);
+    ulonglong char_length= (ulonglong) args[0]->max_char_length() * tmp.count();
+    fix_char_length_ulonglong(char_length);
+    return false;
   }
-  return FALSE;
+  max_length= MAX_BLOB_WIDTH;
+  maybe_null= true;
+  return false;
 }
 
 /**
@@ -3052,26 +3059,14 @@ err:
 bool Item_func_space::fix_length_and_dec()
 {
   collation.set(default_charset(), DERIVATION_COERCIBLE, MY_REPERTOIRE_ASCII);
-  if (args[0]->const_item())
+  if (args[0]->const_item() && !args[0]->is_expensive())
   {
-    /* must be longlong to avoid truncation */
-    longlong count= args[0]->val_int();
-    if (args[0]->null_value)
-      goto end;
-    /*
-     Assumes that the maximum length of a String is < INT_MAX32.
-     Set here so that rest of code sees out-of-bound value as such.
-    */
-    if (count > INT_MAX32)
-      count= INT_MAX32;
-    fix_char_length_ulonglong(count);
-    return FALSE;
+    fix_char_length_ulonglong(Repeat_count(args[0]).count());
+    return false;
   }
-
-end:
   max_length= MAX_BLOB_WIDTH;
-  maybe_null= 1;
-  return FALSE;
+  maybe_null= true;
+  return false;
 }
 
 
@@ -3182,24 +3177,15 @@ bool Item_func_pad::fix_length_and_dec()
     pad_str.append(" ", 1);
   }
 
-  if (args[1]->const_item())
-  {
-    ulonglong char_length= (ulonglong) args[1]->val_int();
-    DBUG_ASSERT(collation.collation->mbmaxlen > 0);
-    /* Assumes that the maximum length of a String is < INT_MAX32. */
-    /* Set here so that rest of code sees out-of-bound value as such. */
-    if (args[1]->null_value)
-      char_length= 0;
-    else if (char_length > INT_MAX32)
-      char_length= INT_MAX32;
-    fix_char_length_ulonglong(char_length);
-  }
-  else
+  DBUG_ASSERT(collation.collation->mbmaxlen > 0);
+  if (args[1]->const_item() && !args[1]->is_expensive())
   {
-    max_length= MAX_BLOB_WIDTH;
-    maybe_null= 1;
+    fix_char_length(Repeat_count(args[1]).count());
+    return false;
   }
-  return FALSE;
+  max_length= MAX_BLOB_WIDTH;
+  maybe_null= true;
+  return false;
 }