MDEV-8472 BINARY, VARBINARY and BLOB return different warnings on CAST to DECIMAL

mysql-test/r/type_binary.result

@@ -146,3 +146,37 @@ hex(f2)	hex(f3)
 0000	
 drop table t1;
 End of 5.0 tests
+#
+# Start of 10.0 tests
+#
+#
+# MDEV-8472 BINARY, VARBINARY and BLOB return different warnings on CAST to DECIMAL
+#
+SET NAMES utf8;
+CREATE TABLE t1 (a BINARY(30));
+INSERT INTO t1 VALUES ('1äÖüß@µ*$');
+SELECT CAST(a AS DECIMAL) FROM t1;
+CAST(a AS DECIMAL)
+1
+Warnings:
+Warning	1292	Truncated incorrect DECIMAL value: '1\xC3\xA4\xC3\x96\xC3\xBC\xC3\x9F@\xC2\xB5*$\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
+DROP TABLE t1;
+CREATE TABLE t1 (a VARBINARY(30));
+INSERT INTO t1 VALUES ('1äÖüß@µ*$');
+SELECT CAST(a AS DECIMAL) FROM t1;
+CAST(a AS DECIMAL)
+1
+Warnings:
+Warning	1292	Truncated incorrect DECIMAL value: '1\xC3\xA4\xC3\x96\xC3\xBC\xC3\x9F@\xC2\xB5*$'
+DROP TABLE t1;
+CREATE TABLE t1 (a BLOB);
+INSERT INTO t1 VALUES ('1äÖüß@µ*$');
+SELECT CAST(a AS DECIMAL) FROM t1;
+CAST(a AS DECIMAL)
+1
+Warnings:
+Warning	1292	Truncated incorrect DECIMAL value: '1\xC3\xA4\xC3\x96\xC3\xBC\xC3\x9F@\xC2\xB5*$'
+DROP TABLE t1;
+#
+# End of 10.0 tests
+#

mysql-test/t/type_binary.test

@@ -100,3 +100,29 @@ select hex(f2), hex(f3) from t1;
 drop table t1;
 
 --echo End of 5.0 tests
+
+--echo #
+--echo # Start of 10.0 tests
+--echo #
+
+--echo #
+--echo # MDEV-8472 BINARY, VARBINARY and BLOB return different warnings on CAST to DECIMAL
+--echo #
+SET NAMES utf8;
+CREATE TABLE t1 (a BINARY(30));
+INSERT INTO t1 VALUES ('1äÖüß@µ*$');
+SELECT CAST(a AS DECIMAL) FROM t1;
+DROP TABLE t1;
+CREATE TABLE t1 (a VARBINARY(30));
+INSERT INTO t1 VALUES ('1äÖüß@µ*$');
+SELECT CAST(a AS DECIMAL) FROM t1;
+DROP TABLE t1;
+CREATE TABLE t1 (a BLOB);
+INSERT INTO t1 VALUES ('1äÖüß@µ*$');
+SELECT CAST(a AS DECIMAL) FROM t1;
+DROP TABLE t1;
+
+--echo #
+--echo # End of 10.0 tests
+--echo #
+

sql/field.cc

@@ -6500,24 +6500,32 @@ String *Field_string::val_str(String *val_buffer __attribute__((unused)),
 }
 
 
-my_decimal *Field_string::val_decimal(my_decimal *decimal_value)
+my_decimal *Field_longstr::val_decimal_from_str(const char *str,
+                                                uint length,
+                                                CHARSET_INFO *cs,
+                                                my_decimal *decimal_value)
 {
-  ASSERT_COLUMN_MARKED_FOR_READ;
-  int err= str2my_decimal(E_DEC_FATAL_ERROR, (char*) ptr, field_length,
-                          charset(), decimal_value);
+  int err= str2my_decimal(E_DEC_FATAL_ERROR, str, length, cs, decimal_value);
   if (!get_thd()->no_errors && err)
   {
-    ErrConvString errmsg((char*) ptr, field_length, charset());
+    ErrConvString errmsg(str, length, cs);
     push_warning_printf(current_thd, Sql_condition::WARN_LEVEL_WARN,
                         ER_TRUNCATED_WRONG_VALUE, 
                         ER(ER_TRUNCATED_WRONG_VALUE),
                         "DECIMAL", errmsg.ptr());
   }
-
   return decimal_value;
 }
 
 
+my_decimal *Field_string::val_decimal(my_decimal *decimal_value)
+{
+  ASSERT_COLUMN_MARKED_FOR_READ;
+  return val_decimal_from_str((const char *) ptr, field_length,
+                              Field_string::charset(), decimal_value);
+}
+
+
 struct Check_field_param {
   Field *field;
 };
@@ -6942,18 +6950,9 @@ String *Field_varstring::val_str(String *val_buffer __attribute__((unused)),
 my_decimal *Field_varstring::val_decimal(my_decimal *decimal_value)
 {
   ASSERT_COLUMN_MARKED_FOR_READ;
-  CHARSET_INFO *cs= charset();
   uint length= length_bytes == 1 ? (uint) *ptr : uint2korr(ptr);
-  int error= str2my_decimal(E_DEC_FATAL_ERROR, (char*) ptr+length_bytes, length,
-                 cs, decimal_value);
-
-  if (!get_thd()->no_errors && error)
-  {
-    push_numerical_conversion_warning(current_thd, (char*)ptr+length_bytes, 
-                                      length, cs, "DECIMAL", 
-                                      ER_TRUNCATED_WRONG_VALUE); 
-  }
-  return decimal_value;
+  return val_decimal_from_str((const char *) ptr + length_bytes, length,
+                              Field_varstring::charset(), decimal_value);
 }
 
 
@@ -7474,9 +7473,8 @@ my_decimal *Field_blob::val_decimal(my_decimal *decimal_value)
   else
     length= get_length(ptr);
 
-  str2my_decimal(E_DEC_FATAL_ERROR, blob, length, charset(),
-                 decimal_value);
-  return decimal_value;
+  return val_decimal_from_str(blob, length,
+                              Field_blob::charset(), decimal_value);
 }
 
 

sql/field.h

@@ -1161,6 +1161,9 @@ protected:
                                const char *cannot_convert_error_pos,
                                const char *end,
                                CHARSET_INFO *cs);
+  my_decimal *val_decimal_from_str(const char *str, uint length,
+                                   CHARSET_INFO *cs,
+                                   my_decimal *decimal_value);
 public:
   Field_longstr(uchar *ptr_arg, uint32 len_arg, uchar *null_ptr_arg,
                 uchar null_bit_arg, utype unireg_check_arg,