Merge branch '10.1' into 10.2

1 files changed, 130 insertions, 100 deletions

diff --git a/sql/item_strfunc.cc b/sql/item_strfunc.cc
index e91cf64fd04..3c2b2374f1e 100644
--- a/sql/item_strfunc.cc
+++ b/sql/item_strfunc.cc
@@ -66,8 +66,14 @@ size_t username_char_length= 80;
   Conversion happens only in case of "tricky" Item character set (e.g. UCS2).
   Normally conversion does not happen, and val_str_ascii() is immediately
   returned instead.
+
+  No matter if conversion is needed or not needed,
+  the result is always returned in "str" (see MDEV-10306 why).
+
+  @param [OUT] str          - Store the result here
+  @param [IN]  ascii_buffer - Use this temporary buffer to call val_str_ascii()
 */
-String *Item_func::val_str_from_val_str_ascii(String *str, String *str2)
+String *Item_func::val_str_from_val_str_ascii(String *str, String *ascii_buffer)
 {
   DBUG_ASSERT(fixed == 1);
 
@@ -79,19 +85,19 @@ String *Item_func::val_str_from_val_str_ascii(String *str, String *str2)
     return res;
   }
   
-  DBUG_ASSERT(str != str2);
+  DBUG_ASSERT(str != ascii_buffer);
   
   uint errors;
-  String *res= val_str_ascii(str);
+  String *res= val_str_ascii(ascii_buffer);
   if (!res)
     return 0;
   
-  if ((null_value= str2->copy(res->ptr(), res->length(),
-                              &my_charset_latin1, collation.collation,
-                              &errors)))
+  if ((null_value= str->copy(res->ptr(), res->length(),
+                             &my_charset_latin1, collation.collation,
+                             &errors)))
     return 0;
   
-  return str2;
+  return str;
 }
 
 
@@ -307,11 +313,11 @@ void Item_aes_crypt::create_key(String *user_key, uchar *real_key)
 }
 
 
-String *Item_aes_crypt::val_str(String *str)
+String *Item_aes_crypt::val_str(String *str2)
 {
   DBUG_ASSERT(fixed == 1);
   StringBuffer<80> user_key_buf;
-  String *sptr= args[0]->val_str(str);
+  String *sptr= args[0]->val_str(&str_value);
   String *user_key=  args[1]->val_str(&user_key_buf);
   uint32 aes_length;
 
@@ -320,17 +326,17 @@ String *Item_aes_crypt::val_str(String *str)
     null_value=0;
     aes_length=my_aes_get_size(MY_AES_ECB, sptr->length());
 
-    if (!str_value.alloc(aes_length))		// Ensure that memory is free
+    if (!str2->alloc(aes_length))		// Ensure that memory is free
     {
       uchar rkey[AES_KEY_LENGTH / 8];
       create_key(user_key, rkey);
 
       if (!my_aes_crypt(MY_AES_ECB, what, (uchar*)sptr->ptr(), sptr->length(),
-                 (uchar*)str_value.ptr(), &aes_length,
+                 (uchar*)str2->ptr(), &aes_length,
                  rkey, AES_KEY_LENGTH / 8, 0, 0))
       {
-        str_value.length((uint) aes_length);
-        return &str_value;
+        str2->length((uint) aes_length);
+        return str2;
       }
     }
   }
@@ -345,6 +351,7 @@ void Item_func_aes_encrypt::fix_length_and_dec()
 }
 
 
+
 void Item_func_aes_decrypt::fix_length_and_dec()
 {
   max_length=args[0]->max_length;
@@ -373,7 +380,7 @@ void Item_func_to_base64::fix_length_and_dec()
 
 String *Item_func_to_base64::val_str_ascii(String *str)
 {
-  String *res= args[0]->val_str(str);
+  String *res= args[0]->val_str(&tmp_value);
   bool too_long= false;
   int length;
   if (!res ||
@@ -381,7 +388,7 @@ String *Item_func_to_base64::val_str_ascii(String *str)
       (too_long=
        ((uint) (length= my_base64_needed_encoded_length((int) res->length())) >
         current_thd->variables.max_allowed_packet)) ||
-      tmp_value.alloc((uint) length))
+      str->alloc((uint) length))
   {
     null_value= 1; // NULL input, too long input, or OOM.
     if (too_long)
@@ -395,11 +402,11 @@ String *Item_func_to_base64::val_str_ascii(String *str)
     }
     return 0;
   }
-  my_base64_encode(res->ptr(), (int) res->length(), (char*) tmp_value.ptr());
+  my_base64_encode(res->ptr(), (int) res->length(), (char*) str->ptr());
   DBUG_ASSERT(length > 0);
-  tmp_value.length((uint) length - 1); // Without trailing '\0'
+  str->length((uint) length - 1); // Without trailing '\0'
   null_value= 0;
-  return &tmp_value;
+  return str;
 }
 
 
@@ -420,7 +427,7 @@ void Item_func_from_base64::fix_length_and_dec()
 
 String *Item_func_from_base64::val_str(String *str)
 {
-  String *res= args[0]->val_str_ascii(str);
+  String *res= args[0]->val_str_ascii(&tmp_value);
   int length;
   const char *end_ptr;
 
@@ -440,11 +447,11 @@ String *Item_func_from_base64::val_str(String *str)
     goto err;
   }
 
-  if (tmp_value.alloc((uint) length))
+  if (str->alloc((uint) length))
     goto err;
 
   if ((length= my_base64_decode(res->ptr(), (int) res->length(),
-                             (char *) tmp_value.ptr(), &end_ptr, 0)) < 0 ||
+                                (char *) str->ptr(), &end_ptr, 0)) < 0 ||
       end_ptr < res->ptr() + res->length())
   {
     THD *thd= current_thd;
@@ -454,9 +461,9 @@ String *Item_func_from_base64::val_str(String *str)
     goto err;
   }
 
-  tmp_value.length((uint) length);
+  str->length((uint) length);
   null_value= 0;
-  return &tmp_value;
+  return str;
 err:
   null_value= 1; // NULL input, too long input, OOM, or badly formed input
   return 0;
@@ -712,7 +719,7 @@ String *Item_func_des_encrypt::val_str(String *str)
   struct st_des_keyschedule keyschedule;
   const char *append_str="********";
   uint key_number, res_length, tail;
-  String *res= args[0]->val_str(str);
+  String *res= args[0]->val_str(&tmp_value);
 
   if ((null_value= args[0]->null_value))
     return 0;                                   // ENCRYPT(NULL) == NULL
@@ -736,7 +743,7 @@ String *Item_func_des_encrypt::val_str(String *str)
   }
   else
   {
-    String *keystr=args[1]->val_str(&tmp_value);
+    String *keystr= args[1]->val_str(str);
     if (!keystr)
       goto error;
     key_number=127;				// User key string
@@ -768,23 +775,23 @@ String *Item_func_des_encrypt::val_str(String *str)
   tmp_arg.length(0);
   tmp_arg.append(res->ptr(), res->length());
   code= ER_OUT_OF_RESOURCES;
-  if (tmp_arg.append(append_str, tail) || tmp_value.alloc(res_length+1))
+  if (tmp_arg.append(append_str, tail) || str->alloc(res_length+1))
     goto error;
   tmp_arg[res_length-1]=tail;                   // save extra length
-  tmp_value.realloc(res_length+1);
-  tmp_value.length(res_length+1);
-  tmp_value.set_charset(&my_charset_bin);
-  tmp_value[0]=(char) (128 | key_number);
+  str->realloc(res_length+1);
+  str->length(res_length+1);
+  str->set_charset(&my_charset_bin);
+  (*str)[0]=(char) (128 | key_number);
   // Real encryption
   bzero((char*) &ivec,sizeof(ivec));
   DES_ede3_cbc_encrypt((const uchar*) (tmp_arg.ptr()),
-		       (uchar*) (tmp_value.ptr()+1),
+		       (uchar*) (str->ptr()+1),
 		       res_length,
 		       &keyschedule.ks1,
 		       &keyschedule.ks2,
 		       &keyschedule.ks3,
 		       &ivec, TRUE);
-  return &tmp_value;
+  return str;
 
 error:
   THD *thd= current_thd;
@@ -810,7 +817,7 @@ String *Item_func_des_decrypt::val_str(String *str)
   DES_cblock ivec;
   struct st_des_keyblock keyblock;
   struct st_des_keyschedule keyschedule;
-  String *res= args[0]->val_str(str);
+  String *res= args[0]->val_str(&tmp_value);
   uint length,tail;
 
   if ((null_value= args[0]->null_value))
@@ -834,7 +841,7 @@ String *Item_func_des_decrypt::val_str(String *str)
   else
   {
     // We make good 24-byte (168 bit) key from given plaintext key with MD5
-    String *keystr=args[1]->val_str(&tmp_value);
+    String *keystr= args[1]->val_str(str);
     if (!keystr)
       goto error;
 
@@ -849,23 +856,23 @@ String *Item_func_des_decrypt::val_str(String *str)
     DES_set_key_unchecked(&keyblock.key3,&keyschedule.ks3);
   }
   code= ER_OUT_OF_RESOURCES;
-  if (tmp_value.alloc(length-1))
+  if (str->alloc(length-1))
     goto error;
 
   bzero((char*) &ivec,sizeof(ivec));
   DES_ede3_cbc_encrypt((const uchar*) res->ptr()+1,
-		       (uchar*) (tmp_value.ptr()),
+		       (uchar*) (str->ptr()),
 		       length-1,
 		       &keyschedule.ks1,
 		       &keyschedule.ks2,
 		       &keyschedule.ks3,
 		       &ivec, FALSE);
   /* Restore old length of key */
-  if ((tail=(uint) (uchar) tmp_value[length-2]) > 8)
+  if ((tail=(uint) (uchar) (*str)[length-2]) > 8)
     goto wrong_key;				     // Wrong key
-  tmp_value.length(length-1-tail);
-  tmp_value.set_charset(&my_charset_bin);
-  return &tmp_value;
+  str->length(length-1-tail);
+  str->set_charset(&my_charset_bin);
+  return str;
 
 error:
   {
@@ -1063,25 +1070,26 @@ void Item_func_concat_ws::fix_length_and_dec()
 String *Item_func_reverse::val_str(String *str)
 {
   DBUG_ASSERT(fixed == 1);
-  String *res = args[0]->val_str(str);
-  char *ptr, *end, *tmp;
+  String *res= args[0]->val_str(&tmp_value);
+  const char *ptr, *end;
+  char *tmp;
 
   if ((null_value=args[0]->null_value))
     return 0;
   /* An empty string is a special case as the string pointer may be null */
   if (!res->length())
     return make_empty_result();
-  if (tmp_value.alloced_length() < res->length() &&
-      tmp_value.realloc(res->length()))
+  if (str->alloced_length() < res->length() &&
+      str->realloc(res->length()))
   {
     null_value= 1;
     return 0;
   }
-  tmp_value.length(res->length());
-  tmp_value.set_charset(res->charset());
-  ptr= (char *) res->ptr();
-  end= ptr + res->length();
-  tmp= (char *) tmp_value.ptr() + tmp_value.length();
+  str->length(res->length());
+  str->set_charset(res->charset());
+  ptr= res->ptr();
+  end= res->end();
+  tmp= (char *) str->end();
 #ifdef USE_MB
   if (use_mb(res->charset()))
   {
@@ -1091,7 +1099,7 @@ String *Item_func_reverse::val_str(String *str)
       if ((l= my_ismbchar(res->charset(),ptr,end)))
       {
         tmp-= l;
-        DBUG_ASSERT(tmp >= tmp_value.ptr());
+        DBUG_ASSERT(tmp >= str->ptr());
         memcpy(tmp,ptr,l);
         ptr+= l;
       }
@@ -1105,7 +1113,7 @@ String *Item_func_reverse::val_str(String *str)
     while (ptr < end)
       *--tmp= *ptr++;
   }
-  return &tmp_value;
+  return str;
 }
 
 
@@ -2285,6 +2293,7 @@ String *Item_func_database::val_str(String *str)
   }
   else
     str->copy(thd->db, thd->db_length, system_charset_info);
+  null_value= 0;
   return str;
 }
 
@@ -2319,6 +2328,28 @@ bool Item_func_user::init(const char *user, const char *host)
 }
 
 
+Item *Item_func_sysconst::safe_charset_converter(THD *thd, CHARSET_INFO *tocs)
+{
+  /*
+   During view or prepared statement creation, the item should not
+   make use of const_charset_converter as it would imply substitution
+   with constant items which is not correct. Functions can have different
+   values during view creation and view execution based on context.
+
+   Return the identical item during view creation and prepare.
+  */
+  if (thd->lex->is_ps_or_view_context_analysis())
+    return this;
+  return const_charset_converter(thd, tocs, true, fully_qualified_func_name());
+}
+
+bool Item_func_sysconst::const_item() const
+{
+  if (current_thd->lex->is_ps_or_view_context_analysis())
+    return false;
+  return true;
+}
+
 bool Item_func_user::fix_fields(THD *thd, Item **ref)
 {
   return (Item_func_sysconst::fix_fields(thd, ref) ||
@@ -2344,15 +2375,13 @@ bool Item_func_current_role::fix_fields(THD *thd, Item **ref)
 
   Security_context *ctx= context && context->security_ctx
                           ? context->security_ctx : thd->security_ctx;
-
   if (ctx->priv_role[0])
   {
     if (str_value.copy(ctx->priv_role, strlen(ctx->priv_role),
                        system_charset_info))
       return 1;
-
-    null_value= maybe_null= 0;
     str_value.mark_as_const();
+    null_value= maybe_null= 0;
     return 0;
   }
   null_value= maybe_null= 1;
@@ -2366,7 +2395,6 @@ void Item_func_soundex::fix_length_and_dec()
   DBUG_ASSERT(collation.collation != NULL);
   set_if_bigger(char_length, 4);
   fix_char_length(char_length);
-  tmp_value.set_charset(collation.collation);
 }
 
 
@@ -2411,7 +2439,7 @@ static bool my_uni_isalpha(int wc)
 String *Item_func_soundex::val_str(String *str)
 {
   DBUG_ASSERT(fixed == 1);
-  String *res  =args[0]->val_str(str);
+  String *res= args[0]->val_str(&tmp_value);
   char last_ch,ch;
   CHARSET_INFO *cs= collation.collation;
   my_wc_t wc;
@@ -2421,10 +2449,11 @@ String *Item_func_soundex::val_str(String *str)
   if ((null_value= args[0]->null_value))
     return 0; /* purecov: inspected */
 
-  if (tmp_value.alloc(MY_MAX(res->length(), 4 * cs->mbminlen)))
-    return str; /* purecov: inspected */
-  char *to= (char *) tmp_value.ptr();
-  char *to_end= to + tmp_value.alloced_length();
+  if (str->alloc(MY_MAX(res->length(), 4 * cs->mbminlen)))
+    return &tmp_value; /* purecov: inspected */
+  str->set_charset(collation.collation);
+  char *to= (char *) str->ptr();
+  char *to_end= to + str->alloced_length();
   char *from= (char *) res->ptr(), *end= from + res->length();
   
   for ( ; ; ) /* Skip pre-space */
@@ -2509,8 +2538,8 @@ String *Item_func_soundex::val_str(String *str)
     to+= nbytes;
   }
 
-  tmp_value.length((uint) (to-tmp_value.ptr()));
-  return &tmp_value;
+  str->length((uint) (to - str->ptr()));
+  return str;
 }
 
 
@@ -3332,13 +3361,13 @@ String *Item_func_conv_charset::val_str(String *str)
   DBUG_ASSERT(fixed == 1);
   if (use_cached_value)
     return null_value ? 0 : &str_value;
-  String *arg= args[0]->val_str(str);
+  String *arg= args[0]->val_str(&tmp_value);
   String_copier_for_item copier(current_thd);
   return ((null_value= args[0]->null_value ||
-                       copier.copy_with_warn(collation.collation, &tmp_value,
+                       copier.copy_with_warn(collation.collation, str,
                                              arg->charset(), arg->ptr(),
                                              arg->length(), arg->length()))) ?
-    0 : &tmp_value;
+    0 : str;
 }
 
 void Item_func_conv_charset::fix_length_and_dec()
@@ -3479,7 +3508,7 @@ String *Item_func_weight_string::val_str(String *str)
   DBUG_ASSERT(fixed == 1);
 
   if (args[0]->result_type() != STRING_RESULT ||
-      !(res= args[0]->val_str(str)))
+      !(res= args[0]->val_str(&tmp_value)))
     goto nl;
   
   /*
@@ -3529,19 +3558,20 @@ String *Item_func_weight_string::val_str(String *str)
       goto nl;
     }
   }
-  if (tmp_value.alloc(tmp_length))
+
+  if (str->alloc(tmp_length))
     goto nl;
 
   frm_length= cs->coll->strnxfrm(cs,
-                                 (uchar *) tmp_value.ptr(), tmp_length,
+                                 (uchar *) str->ptr(), tmp_length,
                                  nweights ? nweights : tmp_length,
                                  (const uchar *) res->ptr(), res->length(),
                                  flags);
   DBUG_ASSERT(frm_length <= tmp_length);
 
-  tmp_value.length(frm_length);
+  str->length(frm_length);
   null_value= 0;
-  return &tmp_value;
+  return str;
 
 nl:
   null_value= 1;
@@ -3597,18 +3627,18 @@ String *Item_func_hex::val_str_ascii(String *str)
   }
 
   /* Convert given string to a hex string, character by character */
-  res= args[0]->val_str(str);
-  if (!res || tmp_value.alloc(res->length()*2+1))
+  res= args[0]->val_str(&tmp_value);
+  if (!res || str->alloc(res->length()*2+1))
   {
     null_value=1;
     return 0;
   }
   null_value=0;
-  tmp_value.length(res->length()*2);
-  tmp_value.set_charset(&my_charset_latin1);
+  str->length(res->length()*2);
+  str->set_charset(&my_charset_latin1);
 
-  octet2hex((char*) tmp_value.ptr(), res->ptr(), res->length());
-  return &tmp_value;
+  octet2hex((char*) str->ptr(), res->ptr(), res->length());
+  return str;
 }
 
   /** Convert given hex string to a binary string. */
@@ -3621,8 +3651,8 @@ String *Item_func_unhex::val_str(String *str)
   uint length;
   DBUG_ASSERT(fixed == 1);
 
-  res= args[0]->val_str(str);
-  if (!res || tmp_value.alloc(length= (1+res->length())/2))
+  res= args[0]->val_str(&tmp_value);
+  if (!res || str->alloc(length= (1+res->length())/2))
   {
     null_value=1;
     return 0;
@@ -3630,8 +3660,8 @@ String *Item_func_unhex::val_str(String *str)
 
   from= res->ptr();
   null_value= 0;
-  tmp_value.length(length);
-  to= (char*) tmp_value.ptr();
+  str->length(length);
+  to= (char*) str->ptr();
   if (res->length() % 2)
   {
     int hex_char;
@@ -3649,7 +3679,7 @@ String *Item_func_unhex::val_str(String *str)
     if ((null_value= (hex_char == -1)))
       return 0;
   }
-  return &tmp_value;
+  return str;
 }
 
 
@@ -3900,7 +3930,7 @@ String *Item_func_quote::val_str(String *str)
 
   ulong max_allowed_packet= current_thd->variables.max_allowed_packet;
   char *from, *to, *end, *start;
-  String *arg= args[0]->val_str(str);
+  String *arg= args[0]->val_str(&tmp_value);
   uint arg_length, new_length;
   if (!arg)					// Null argument
   {
@@ -3927,7 +3957,7 @@ String *Item_func_quote::val_str(String *str)
     set_if_smaller(new_length, max_allowed_packet);
   }
 
-  if (tmp_value.alloc(new_length))
+  if (str->alloc(new_length))
     goto null;
 
   if (collation.collation->mbmaxlen > 1)
@@ -3935,7 +3965,7 @@ String *Item_func_quote::val_str(String *str)
     CHARSET_INFO *cs= collation.collation;
     int mblen;
     uchar *to_end;
-    to= (char*) tmp_value.ptr();
+    to= (char*) str->ptr();
     to_end= (uchar*) to + new_length;
 
     /* Put leading quote */
@@ -3972,14 +4002,14 @@ String *Item_func_quote::val_str(String *str)
     if ((mblen= cs->cset->wc_mb(cs, '\'', (uchar *) to, to_end)) <= 0)
       goto toolong;
     to+= mblen;
-    new_length= to - tmp_value.ptr();
+    new_length= to - str->ptr();
     goto ret;
   }
 
   /*
     We replace characters from the end to the beginning
   */
-  to= (char*) tmp_value.ptr() + new_length - 1;
+  to= (char*) str->ptr() + new_length - 1;
   *to--= '\'';
   for (start= (char*) arg->ptr(),end= start + arg_length; end-- != start; to--)
   {
@@ -4009,10 +4039,10 @@ String *Item_func_quote::val_str(String *str)
   *to= '\'';
 
 ret:
-  tmp_value.length(new_length);
-  tmp_value.set_charset(collation.collation);
+  str->length(new_length);
+  str->set_charset(collation.collation);
   null_value= 0;
-  return &tmp_value;
+  return str;
 
 toolong:
   push_warning_printf(current_thd, Sql_condition::WARN_LEVEL_WARN,
@@ -4086,7 +4116,7 @@ String *Item_func_compress::val_str(String *str)
   char *tmp, *last_char;
   DBUG_ASSERT(fixed == 1);
 
-  if (!(res= args[0]->val_str(str)))
+  if (!(res= args[0]->val_str(&tmp_value)))
   {
     null_value= 1;
     return 0;
@@ -4107,13 +4137,13 @@ String *Item_func_compress::val_str(String *str)
 
   // Check new_size overflow: new_size <= res->length()
   if (((uint32) (new_size+5) <= res->length()) || 
-      buffer.realloc((uint32) new_size + 4 + 1))
+      str->realloc((uint32) new_size + 4 + 1))
   {
     null_value= 1;
     return 0;
   }
 
-  body= ((Byte*)buffer.ptr()) + 4;
+  body= ((Byte*)str->ptr()) + 4;
 
   // As far as we have checked res->is_empty() we can use ptr()
   if ((err= my_compress_buffer(body, &new_size, (const uchar *)res->ptr(),
@@ -4127,7 +4157,7 @@ String *Item_func_compress::val_str(String *str)
     return 0;
   }
 
-  tmp= (char*)buffer.ptr(); // int4store is a macro; avoid side effects
+  tmp= (char*) str->ptr(); // int4store is a macro; avoid side effects
   int4store(tmp, res->length() & 0x3FFFFFFF);
 
   /* This is to ensure that things works for CHAR fields, which trim ' ': */
@@ -4138,15 +4168,15 @@ String *Item_func_compress::val_str(String *str)
     new_size++;
   }
 
-  buffer.length((uint32)new_size + 4);
-  return &buffer;
+  str->length((uint32)new_size + 4);
+  return str;
 }
 
 
 String *Item_func_uncompress::val_str(String *str)
 {
   DBUG_ASSERT(fixed == 1);
-  String *res= args[0]->val_str(str);
+  String *res= args[0]->val_str(&tmp_value);
   ulong new_size;
   int err;
   uint code;
@@ -4179,14 +4209,14 @@ String *Item_func_uncompress::val_str(String *str)
                                          max_allowed_packet));
     goto err;
   }
-  if (buffer.realloc((uint32)new_size))
+  if (str->realloc((uint32)new_size))
     goto err;
 
-  if ((err= uncompress((Byte*)buffer.ptr(), &new_size,
+  if ((err= uncompress((Byte*)str->ptr(), &new_size,
 		       ((const Bytef*)res->ptr())+4,res->length()-4)) == Z_OK)
   {
-    buffer.length((uint32) new_size);
-    return &buffer;
+    str->length((uint32) new_size);
+    return str;
   }
 
   code= ((err == Z_BUF_ERROR) ? ER_ZLIB_Z_BUF_ERROR :