- MDEV-6695 Bad column name for UCS2 string literals

  The Item_string constructors called set_name() on the source string,
  which was wrong because in case of UCS2/UTF16/UTF32 the source value
  might be a not well formed string (e.g. have incomplete leftmost character).
  Now set_name() is called on str_value after its copied 
  (with optionally left zero padding) from the source string.
- MDEV-6694 Illegal mix of collation with a PS parameter
  Item_param::convert_str_value() did not set repertoire.
  Introducing a new structure MY_STRING_METADATA to collect
  character length and repertoire of a string in a single loop,
  to avoid two separate loops. Adding a new class Item_basic_value::Metadata
  as a convenience wrapper around MY_STRING_METADATA, to reuse the
  code between Item_string and Item_param.

include/m_ctype.h

@@ -735,6 +735,14 @@ my_bool my_propagate_simple(CHARSET_INFO *cs, const uchar *str, size_t len);
 my_bool my_propagate_complex(CHARSET_INFO *cs, const uchar *str, size_t len);
 
 
+typedef struct 
+{
+  size_t char_length;
+  uint repertoire;
+} MY_STRING_METADATA;
+
+void my_string_metadata_get(MY_STRING_METADATA *metadata,
+                            CHARSET_INFO *cs, const char *str, size_t len);
 uint my_string_repertoire(CHARSET_INFO *cs, const char *str, ulong len);
 my_bool my_charset_is_ascii_based(CHARSET_INFO *cs);
 my_bool my_charset_is_8bit_pure_ascii(CHARSET_INFO *cs);

mysql-test/r/ctype_ucs.result

@@ -5333,5 +5333,12 @@ SELECT CONCAT(CONVERT('pi=' USING ucs2),PI()) AS PI;
 PI
 pi=3.141593
 #
+# MDEV-6695 Bad column name for UCS2 string literals
+#
+SET NAMES utf8, character_set_connection=ucs2;
+SELECT 'a','aa';
+a	aa
+a	aa
+#
 # End of 10.0 tests
 #

mysql-test/r/ctype_utf8.result

@@ -6008,5 +6008,28 @@ CONCAT(a, IF(b>10, _utf8 X'61', _utf8 B'01100001'))
 aa
 DROP TABLE t1;
 #
+#  MDEV-6694 Illegal mix of collation with a PS parameter
+#
+SET NAMES utf8;
+CREATE TABLE t1 (a INT, b VARCHAR(10) CHARACTER SET latin1);
+INSERT INTO t1 VALUES (1,'a');
+SELECT CONCAT(b,IF(a,'b','b')) FROM t1;
+CONCAT(b,IF(a,'b','b'))
+ab
+PREPARE stmt FROM "SELECT CONCAT(b,IF(a,?,?)) FROM t1";
+SET @b='b';
+EXECUTE stmt USING @b,@b;
+CONCAT(b,IF(a,?,?))
+ab
+SET @b='';
+EXECUTE stmt USING @b,@b;
+CONCAT(b,IF(a,?,?))
+a
+SET @b='я';
+EXECUTE stmt USING @b,@b;
+ERROR HY000: Illegal mix of collations (latin1_swedish_ci,IMPLICIT) and (utf8_general_ci,COERCIBLE) for operation 'concat'
+DEALLOCATE PREPARE stmt;
+DROP TABLE t1;
+#
 # End of 10.0 tests
 #

mysql-test/t/ctype_ucs.test

@@ -902,6 +902,13 @@ DROP TABLE t1;
 --echo #
 SELECT CONCAT(CONVERT('pi=' USING ucs2),PI()) AS PI;
 
+--echo #
+--echo # MDEV-6695 Bad column name for UCS2 string literals
+--echo #
+SET NAMES utf8, character_set_connection=ucs2;
+SELECT 'a','aa';
+
+
 --echo #
 --echo # End of 10.0 tests
 --echo #

mysql-test/t/ctype_utf8.test

@@ -1719,6 +1719,24 @@ SELECT CONCAT(a, IF(b>10, _utf8 X'61', _utf8 X'61')) FROM t1;
 SELECT CONCAT(a, IF(b>10, _utf8 X'61', _utf8 B'01100001')) FROM t1;
 DROP TABLE t1;
 
+--echo #
+--echo #  MDEV-6694 Illegal mix of collation with a PS parameter
+--echo #
+SET NAMES utf8;
+CREATE TABLE t1 (a INT, b VARCHAR(10) CHARACTER SET latin1);
+INSERT INTO t1 VALUES (1,'a');
+SELECT CONCAT(b,IF(a,'b','b')) FROM t1;
+PREPARE stmt FROM "SELECT CONCAT(b,IF(a,?,?)) FROM t1";
+SET @b='b';
+EXECUTE stmt USING @b,@b;
+SET @b='';
+EXECUTE stmt USING @b,@b;
+SET @b='я';
+--error ER_CANT_AGGREGATE_2COLLATIONS
+EXECUTE stmt USING @b,@b;
+DEALLOCATE PREPARE stmt;
+DROP TABLE t1;
+
 
 --echo #
 --echo # End of 10.0 tests

sql/item.cc

@@ -1073,10 +1073,14 @@ void Item::set_name(const char *str, uint length, CHARSET_INFO *cs)
     name_length= 0;
     return;
   }
-  if (cs->ctype)
-  {
-    const char *str_start= str;
 
+  const char *str_start= str;
+  if (!cs->ctype || cs->mbminlen > 1)
+  {
+    str+= cs->cset->scan(cs, str, str + length, MY_SEQ_SPACES);
+  }
+  else
+  {
     /*
       This will probably need a better implementation in the future:
       a function in CHARSET_INFO structure.
@@ -1086,6 +1090,7 @@ void Item::set_name(const char *str, uint length, CHARSET_INFO *cs)
       length--;
       str++;
     }
+  }
   if (str != str_start && !is_autogenerated_name)
   {
     char buff[SAFE_NAME_LEN];
@@ -1101,7 +1106,6 @@ void Item::set_name(const char *str, uint length, CHARSET_INFO *cs)
                           ER_REMOVED_SPACES, ER(ER_REMOVED_SPACES),
                           buff);
   }
-  }
   if (!my_charset_same(cs, system_charset_info))
   {
     size_t res_length;
@@ -1269,27 +1273,11 @@ Item *Item_param::safe_charset_converter(CHARSET_INFO *tocs)
     SET @@arg= 1;
     EXECUTE stms USING @arg;
 
-    result_type is STRING_RESULT at prepare time,
+    In the above example result_type is STRING_RESULT at prepare time,
     and INT_RESULT at execution time.
   */
-  if (const_item())
-  {
-    if (state == NULL_VALUE)
-      return this;
-    uint cnv_errors;
-    String *ostr= val_str(&cnvstr);
-    if (!needs_charset_converter(tocs))
-      return this;
-    cnvitem->copy_value(ostr->ptr(), ostr->length(),
-                        ostr->charset(), tocs, &cnv_errors);
-    if (cnv_errors)
-       return NULL;
-    if (ostr->charset() == &my_charset_bin && tocs != &my_charset_bin &&
-        !cnvitem->check_well_formed_result(true))
-      return NULL;
-    return cnvitem;
-  }
-  return this;
+  return !const_item() || state == NULL_VALUE ?
+         this : const_charset_converter(tocs, true);
 }
 
 
@@ -3175,8 +3163,6 @@ Item_param::Item_param(uint pos_in_query_arg) :
     value is set.
   */
   maybe_null= 1;
-  cnvitem= new Item_string("", 0, &my_charset_bin, DERIVATION_COERCIBLE);
-  cnvstr.set(cnvbuf, sizeof(cnvbuf), &my_charset_bin);
 }
 
 
@@ -3736,18 +3722,14 @@ bool Item_param::convert_str_value(THD *thd)
       str_value.set_charset(value.cs_info.final_character_set_of_str_value);
     /* Here str_value is guaranteed to be in final_character_set_of_str_value */
 
-    max_length= str_value.numchars() * str_value.charset()->mbmaxlen;
-
-    /* For the strings converted to numeric form within some functions */
-    decimals= NOT_FIXED_DEC;
     /*
       str_value_ptr is returned from val_str(). It must be not alloced
       to prevent it's modification by val_str() invoker.
     */
     str_value_ptr.set(str_value.ptr(), str_value.length(),
                       str_value.charset());
-    /* Synchronize item charset with value charset */
-    collation.set(str_value.charset(), DERIVATION_COERCIBLE);
+    /* Synchronize item charset and length with value charset */
+    fix_charset_and_length_from_str_value(DERIVATION_COERCIBLE);
   }
   return rc;
 }
@@ -3777,7 +3759,8 @@ Item_param::clone_item()
   case STRING_VALUE:
   case LONG_DATA_VALUE:
     return new Item_string(name, str_value.c_ptr_quick(), str_value.length(),
-                           str_value.charset());
+                           str_value.charset(),
+                           collation.derivation, collation.repertoire);
   case TIME_VALUE:
     break;
   case NO_VALUE:

sql/item.h

@@ -1694,7 +1694,41 @@ class Item_basic_value :public Item
       value->bin_eq(other) :
       collation.collation == cs && value->eq(other, collation.collation);
   }
+
 protected:
+  // Value metadata, e.g. to make string processing easier
+  class Metadata: private MY_STRING_METADATA
+  {
+  public:
+    Metadata(const String *str)
+    {
+      my_string_metadata_get(this, str->charset(), str->ptr(), str->length());
+    }
+    Metadata(const String *str, uint repertoire)
+    {
+      MY_STRING_METADATA::repertoire= repertoire;
+      MY_STRING_METADATA::char_length= str->numchars();
+    }
+    uint repertoire() const { return MY_STRING_METADATA::repertoire; }
+    size_t char_length() const { return MY_STRING_METADATA::char_length; }
+  };
+  void fix_charset_and_length_from_str_value(Derivation dv, Metadata metadata)
+  {
+    /*
+      We have to have a different max_length than 'length' here to
+      ensure that we get the right length if we do use the item
+      to create a new table. In this case max_length must be the maximum
+      number of chars for a string of this type because we in Create_field::
+      divide the max_length with mbmaxlen).
+    */
+    collation.set(str_value.charset(), dv, metadata.repertoire());
+    fix_char_length(metadata.char_length());
+    decimals= NOT_FIXED_DEC;
+  }
+  void fix_charset_and_length_from_str_value(Derivation dv)
+  {
+    fix_charset_and_length_from_str_value(dv, Metadata(&str_value));
+  }
   Item_basic_value(): Item() {}
   /*
     In the xxx_eq() methods below we need to cast off "const" to
@@ -2374,10 +2408,6 @@ class Item_null_result :public Item_null
 class Item_param :public Item_basic_value,
                   private Settable_routine_parameter
 {
-  char cnvbuf[MAX_FIELD_WIDTH];
-  String cnvstr;
-  Item_string *cnvitem;
-
 public:
   enum enum_item_param_state
   {
@@ -2727,40 +2757,16 @@ class Item_string :public Item_basic_constant
   {
     m_cs_specified= cs_specified;
   }
-
-public:
-  Item_string(const char *str,uint length,
-              CHARSET_INFO *cs, Derivation dv= DERIVATION_COERCIBLE,
-              uint repertoire= MY_REPERTOIRE_UNICODE30)
-    : m_cs_specified(FALSE)
+  void fix_from_value(Derivation dv, const Metadata metadata)
   {
-    str_value.set_or_copy_aligned(str, length, cs);
-    collation.set(cs, dv, repertoire);
-    /*
-      We have to have a different max_length than 'length' here to
-      ensure that we get the right length if we do use the item
-      to create a new table. In this case max_length must be the maximum
-      number of chars for a string of this type because we in Create_field::
-      divide the max_length with mbmaxlen).
-    */
-    max_length= str_value.numchars()*cs->mbmaxlen;
-    set_name(str, length, cs);
-    decimals=NOT_FIXED_DEC;
+    fix_charset_and_length_from_str_value(dv, metadata);
     // it is constant => can be used without fix_fields (and frequently used)
     fixed= 1;
   }
-  Item_string(const String *str, CHARSET_INFO *tocs, uint *conv_errors,
-              Derivation dv, uint repertoire)
-    :m_cs_specified(false)
+  void fix_and_set_name_from_value(Derivation dv, const Metadata metadata)
   {
-    if (str_value.copy(str, tocs, conv_errors))
-      str_value.set("", 0, tocs); // EOM ?
-    str_value.mark_as_const();
-    collation.set(tocs, dv, repertoire);
-    fix_char_length(str_value.numchars());
-    set_name(str_value.ptr(), str_value.length(), tocs);
-    decimals= NOT_FIXED_DEC;
-    fixed= 1;
+    fix_from_value(dv, metadata);
+    set_name(str_value.ptr(), str_value.length(), str_value.charset());
   }
 protected:
   /* Just create an item and do not fill string representation */
@@ -2769,51 +2775,55 @@ class Item_string :public Item_basic_constant
   {
     collation.set(cs, dv);
     max_length= 0;
-    set_name(NULL, 0, cs);
+    set_name(NULL, 0, system_charset_info);
     decimals= NOT_FIXED_DEC;
     fixed= 1;
   }
 public:
-  Item_string(const char *name_par, const char *str, uint length,
-              CHARSET_INFO *cs, Derivation dv= DERIVATION_COERCIBLE,
-              uint repertoire= MY_REPERTOIRE_UNICODE30)
+  // Constructors with the item name set from its value
+  Item_string(const char *str, uint length, CHARSET_INFO *cs,
+              Derivation dv, uint repertoire)
     : m_cs_specified(FALSE)
   {
     str_value.set_or_copy_aligned(str, length, cs);
-    collation.set(cs, dv, repertoire);
-    max_length= str_value.numchars()*cs->mbmaxlen;
-    set_name(name_par, 0, cs);
-    decimals=NOT_FIXED_DEC;
-    // it is constant => can be used without fix_fields (and frequently used)
-    fixed= 1;
+    fix_and_set_name_from_value(dv, Metadata(&str_value, repertoire));
   }
-  void copy_value(const char *str, uint32 length, CHARSET_INFO *fromcs,
-                  CHARSET_INFO *tocs, uint *cnv_errors)
+  Item_string(const char *str, uint length,
+              CHARSET_INFO *cs, Derivation dv= DERIVATION_COERCIBLE)
+    : m_cs_specified(FALSE)
+  {
+    str_value.set_or_copy_aligned(str, length, cs);
+    fix_and_set_name_from_value(dv, Metadata(&str_value));
+  }
+  Item_string(const String *str, CHARSET_INFO *tocs, uint *conv_errors,
+              Derivation dv, uint repertoire)
+    :m_cs_specified(false)
   {
-    str_value.copy(str, length, fromcs, tocs, cnv_errors);
+    if (str_value.copy(str, tocs, conv_errors))
+      str_value.set("", 0, tocs); // EOM ?
     str_value.mark_as_const();
-    collation.set(tocs);
-    fix_char_length(str_value.numchars());
+    fix_and_set_name_from_value(dv, Metadata(&str_value, repertoire));
   }
-  
-  void print_value(String *to) const
+  // Constructors with an externally provided item name
+  Item_string(const char *name_par, const char *str, uint length,
+              CHARSET_INFO *cs, Derivation dv= DERIVATION_COERCIBLE)
+    :m_cs_specified(false)
   {
-    str_value.print(to);
+    str_value.set_or_copy_aligned(str, length, cs);
+    fix_from_value(dv, Metadata(&str_value));
+    set_name(name_par, 0, system_charset_info);
   }
-  /*
-    This is used in stored procedures to avoid memory leaks and
-    does a deep copy of its argument.
-  */
-  void set_str_with_copy(const char *str_arg, uint length_arg)
+  Item_string(const char *name_par, const char *str, uint length,
+              CHARSET_INFO *cs, Derivation dv, uint repertoire)
+    :m_cs_specified(false)
   {
-    str_value.copy(str_arg, length_arg, collation.collation);
-    max_length= str_value.numchars() * collation.collation->mbmaxlen;
+    str_value.set_or_copy_aligned(str, length, cs);
+    fix_from_value(dv, Metadata(&str_value, repertoire));
+    set_name(name_par, 0, system_charset_info);
   }
-  void set_repertoire_from_value()
+  void print_value(String *to) const
   {
-    collation.repertoire= my_string_repertoire(str_value.charset(),
-                                               str_value.ptr(),
-                                               str_value.length());
+    str_value.print(to);
   }
   enum Type type() const { return STRING_ITEM; }
   double val_real();
@@ -2914,13 +2924,11 @@ class Item_string_with_introducer :public Item_string
   Item_string_with_introducer(const char *str, uint length, CHARSET_INFO *cs)
     :Item_string(str, length, cs)
   {
-     set_repertoire_from_value();
     set_cs_specified(true);
   }
   Item_string_with_introducer(const String *str, CHARSET_INFO *tocs)
     :Item_string(str->ptr(), str->length(), tocs)
   {
-     set_repertoire_from_value();
     set_cs_specified(true);
   }
 };

sql/sql_string.cc

@@ -580,7 +580,7 @@ bool String::append_with_prefill(const char *s,uint32 arg_length,
   return FALSE;
 }
 
-uint32 String::numchars()
+uint32 String::numchars() const
 {
   return str_charset->cset->numchars(str_charset, Ptr, Ptr+str_length);
 }

sql/sql_string.h

@@ -411,7 +411,7 @@ class String
   friend int stringcmp(const String *a,const String *b);
   friend String *copy_if_not_alloced(String *a,String *b,uint32 arg_length);
   friend class Field;
-  uint32 numchars();
+  uint32 numchars() const;
   int charpos(longlong i,uint32 offset=0);
 
   int reserve(uint32 space_needed)

strings/ctype.c

@@ -818,23 +818,102 @@ my_parse_charset_xml(MY_CHARSET_LOADER *loader, const char *buf, size_t len)
 }
 
 
+uint
+my_string_repertoire_8bit(CHARSET_INFO *cs, const char *str, ulong length)
+{
+  const char *strend;
+  if ((cs->state & MY_CS_NONASCII) && length > 0)
+    return MY_REPERTOIRE_UNICODE30;
+  for (strend= str + length; str < strend; str++)
+  {
+    if (((uchar) *str) > 0x7F)
+      return MY_REPERTOIRE_UNICODE30;
+  }
+  return MY_REPERTOIRE_ASCII;
+}
+
+
+static void
+my_string_metadata_init(MY_STRING_METADATA *metadata)
+{
+  metadata->repertoire= MY_REPERTOIRE_ASCII;
+  metadata->char_length= 0;
+}
+
+
+/**
+  This should probably eventually go as a virtual function into
+  MY_CHARSET_HANDLER or MY_COLLATION_HANDLER.
+*/
+static void
+my_string_metadata_get_mb(MY_STRING_METADATA *metadata,
+                          CHARSET_INFO *cs, const char *str, ulong length)
+{
+  const char *strend= str + length;
+  for (my_string_metadata_init(metadata) ;
+       str < strend;
+       metadata->char_length++)
+  {
+    my_wc_t wc;
+    int mblen= cs->cset->mb_wc(cs, &wc, (const uchar *) str,
+                                        (const uchar *) strend);
+    if (mblen > 0) /* Assigned character */
+    {
+      if (wc > 0x7F)
+        metadata->repertoire|= MY_REPERTOIRE_EXTENDED;
+      str+= mblen;
+    }
+    else if (mblen == MY_CS_ILSEQ) /* Bad byte sequence */
+    {
+      metadata->repertoire|= MY_REPERTOIRE_EXTENDED;
+      str++;
+    }
+    else if (mblen > MY_CS_TOOSMALL) /* Unassigned character */ 
+    {
+      metadata->repertoire|= MY_REPERTOIRE_EXTENDED;
+      str+= (-mblen);
+    }
+    else /* Incomplete character, premature end-of-line */
+    {
+      metadata->repertoire|= MY_REPERTOIRE_EXTENDED; /* Just in case */
+      break;
+    }
+  }
+}
+
+
+/**
+  Collect string metadata: length in characters and repertoire.
+*/
+void
+my_string_metadata_get(MY_STRING_METADATA *metadata,
+                       CHARSET_INFO *cs, const char *str, ulong length)
+{
+  if (cs->mbmaxlen == 1 && !(cs->state & MY_CS_NONASCII))
+  {
+    metadata->char_length= length;
+    metadata->repertoire= my_string_repertoire_8bit(cs, str, length);
+  }
+  else
+  {
+    my_string_metadata_get_mb(metadata, cs, str, length);
+  }
+}
+
+
 /*
   Check repertoire: detect pure ascii strings
 */
 uint
 my_string_repertoire(CHARSET_INFO *cs, const char *str, ulong length)
 {
-  const char *strend= str + length;
-  if (cs->mbminlen == 1)
-  {
-    for ( ; str < strend; str++)
+  if (cs->mbminlen == 1 && !(cs->state & MY_CS_NONASCII))
   {
-      if (((uchar) *str) > 0x7F)
-        return MY_REPERTOIRE_UNICODE30;
-    }
+    return my_string_repertoire_8bit(cs, str, length);
   }
   else
   {
+    const char *strend= str + length;
     my_wc_t wc;
     int chlen;
     for (;