The problem was in the validation of the input data for blob types.
When assigned binary data, the character blob types were only checking if
the length of these data is a multiple of the minimum char length for the
destination charset.
And since e.g. UTF-8's minimum character length is 1 (becuase it's
variable length) even byte sequences that are invalid utf-8 strings (e.g.
wrong leading byte etc) were copied verbatim into utf-8 columns when
coming from binary strings or fields.
Storing invalid data into string columns was having all kinds of ill effects
on code that assumed that the encoding data are valid to begin with.
Fixed by additionally checking the incoming binary string for validity when
assigning it to a non-binary string column.
Made sure the conversions to charsets with no known "invalid" ranges
are not covered by the extra check.
Removed trailing spaces.
Test case added.
MDEV-4489 "Replication of big5, cp932, gbk, sjis strings makes wrong values on slave"
has been fixed.
Problem:
String constants of some Asian charsets (big5,cp932,gbk,sjis)
can have backslash '\' (0x5C) in the second byte of multi-byte characters.
Replicating of such constants using the standard '\'-escaping is dangerous.
Therefore, constants of these charsets are replicated using hex notation:
INSERT INTO t1 (a) VALUES (0x815C);
However, 0xHHHH constants do not work well in some cases,
because they can behave as strings and as numbers, depending on context
(for example, depending on the data type of the column in an INSERT statement).
This SQL script was not replicated correctly with statement-based replication:
SET NAMES gbk;
PREPARE STMT FROM 'INSERT INTO t1 (a) VALUES (?)';
SET @a = '1';
EXECUTE STMT USING @a;
The INSERT statement was replicated as:
INSERT INTO t1 (a) VALUES (0x31);
'1' was correctly converted to the number 1 on master.
But the 0x31 constant was treated as number 49 on slave.
Fix:
1. Binary log now uses X'HHHH' instead of 0xHHHH constants.
2. The X'HHHH' constants now work always as strings, in all contexts.
This is the SQL standard compliant behaviour.
After the fix, the above statement is replicated as:
INSERT INTO t1 (a) VALUES (X'31');
X'31' is treated as string '1' on slave, and is correctly converted to 1.
modified:
@ mysql-test/r/ctype_cp932_binlog_stm.result
@ mysql-test/r/select.result
@ mysql-test/r/select_jcl6.result
@ mysql-test/r/select_pkeycache.result
@ mysql-test/r/user_var-binlog.result
@ mysql-test/r/varbinary.result
@ mysql-test/suite/binlog/r/binlog_stm_ctype_ucs.result
@ mysql-test/suite/binlog/r/binlog_stm_mix_innodb_myisam.result
@ mysql-test/suite/rpl/r/rpl_charset_sjis.result
@ mysql-test/suite/rpl/r/rpl_mdev382.result
@ mysql-test/suite/rpl/t/rpl_charset_sjis.test
@ mysql-test/t/ctype_cp932_binlog_stm.test
@ mysql-test/t/select.test
@ mysql-test/t/varbinary.test
Adding and updating tests
@ sql/item.cc
@ sql/item.h
@ sql/sql_yacc.yy
@ sql/sql_lex.cc
Splitting the implementations of X'HH' and 0xHH constants into two
separate classes. Fixing the parser to distinguish the two syntaxes.
@ sql/log_event.cc
Using X'HH' instead of 0xHH for binary logging for string constants
of the "dangerous" charsets.
@ sql/sql_string.h
Adding a helped method String::append_hex().
COLUMNS ARE USED INSIDE A STORED PROCEDURE
Problem: When 'SET' type columns are used in a DML
inside a stored procedure and a NULL value is passed
to that column, replication is breaking.
Analysis: All stored procedure variables used inside
a DML will be substituted with NAME_CONST functions.
While NAME_CONST are used in this particular scenario,
i.e., when NULL value is passed then charset is copied
from 'empty_set_string' member of Field_set class.
The operator '=' overload method inside 'String' class
is not coping str_charset from R.H.S object to L.H.S object.
Hence charset is wrongly copied in the string assignment
Fix: Handle coping str_charset member in operator '=' overload
method.
sql/sql_string.h:
Handled coping str_charset member in operator '=' overload
method.
COLUMNS ARE USED INSIDE A STORED PROCEDURE
Problem: The operator '=' overload method inside
'String' class is not coping str_charset member from
R.H.S object to L.H.S object. Hence charset is wrongly
set while using string assignments
Analaysis: The above mentioned problem is
identified while doing the analaysis of bug#14593883.
Though the test scenario mentioned in the bug page
is not an issue in mysql-5.1 code, the actual root cause
ie., "str_charset member is not copied" exists in the
mysql-5.1 code base.
Fix: Handle coping str_charset member in operator '=' overload
method.
sql/sql_string.h:
Handled coping str_charset member in operator '=' overload
method.
sql/sql_insert.cc:
CREATE ... IF NOT EXISTS may do nothing, but
it is still not a failure. don't forget to my_ok it.
******
CREATE ... IF NOT EXISTS may do nothing, but
it is still not a failure. don't forget to my_ok it.
sql/sql_table.cc:
small cleanup
******
small cleanup
A lot of small fixes and new test cases.
client/mysqlbinlog.cc:
Cast removed
client/mysqltest.cc:
Added missing DBUG_RETURN
include/my_pthread.h:
set_timespec_time_nsec() now only takes one argument
mysql-test/t/date_formats.test:
Remove --disable_ps_protocl as now also ps supports microseconds
mysys/my_uuid.c:
Changed to use my_interval_timer() instead of my_getsystime()
mysys/waiting_threads.c:
Changed to use my_hrtime()
sql/field.h:
Added bool special_const_compare() for fields that may convert values before compare (like year)
sql/field_conv.cc:
Added test to get optimal copying of identical temporal values.
sql/item.cc:
Return that item_int is equal if it's positive, even if unsigned flag is different.
Fixed Item_cache_str::save_in_field() to have identical null check as other similar functions
Added proper NULL check to Item_cache_int::save_in_field()
sql/item_cmpfunc.cc:
Don't call convert_constant_item() if there is nothing that is worth converting.
Simplified test when years should be converted
sql/item_sum.cc:
Mark cache values in Item_sum_hybrid as not constants to ensure they are not replaced by other cache values in compare_datetime()
sql/item_timefunc.cc:
Changed sec_to_time() to take a my_decimal argument to ensure we don't loose any sub seconds.
Added Item_temporal_func::get_time() (This simplifies some things)
sql/mysql_priv.h:
Added Lazy_string_decimal()
sql/mysqld.cc:
Added my_decimal constants max_seconds_for_time_type, time_second_part_factor
sql/table.cc:
Changed expr_arena to be of type CONVENTIONAL_EXECUTION to ensure that we don't loose any items that are created by fix_fields()
sql/tztime.cc:
TIME_to_gmt_sec() now sets *in_dst_time_gap in case of errors
This is needed to be able to detect if timestamp is 0
storage/maria/lockman.c:
Changed from my_getsystime() to set_timespec_time_nsec()
storage/maria/ma_loghandler.c:
Changed from my_getsystime() to my_hrtime()
storage/maria/ma_recovery.c:
Changed from my_getsystime() to mmicrosecond_interval_timer()
storage/maria/unittest/trnman-t.c:
Changed from my_getsystime() to mmicrosecond_interval_timer()
storage/xtradb/handler/ha_innodb.cc:
Added support for new time,datetime and timestamp
unittest/mysys/thr_template.c:
my_getsystime() -> my_interval_timer()
unittest/mysys/waiting_threads-t.c:
my_getsystime() -> my_interval_timer()
sql/event_parse_data.cc:
don't use "not_used" variable
sql/item_timefunc.cc:
Item_temporal_func::fix_length_and_dec()
and other changes
sql/item_timefunc.h:
introducing Item_timefunc::fix_length_and_dec()
sql/share/errmsg.txt:
don't say "column X" in the error message that used not only for columns
Fixed alias bug when compiling with gcc 4.2.4 that caused subselect.test to fail
sql/item.cc:
Removed alias warnings by changing type from char * to const char*
sql/item.h:
Removed alias warnings by changing type from char * to const char*
sql/item_subselect.cc:
Fixed alias bug when compiling with gcc 4.2.4 that caused subselect.test to fail
sql/sql_string.h:
Removed alias warnings by changing type from char * to const char*
storage/heap/hp_test2.c:
Removed SAFEMALLOC to get rid of compiler error
Fixed test case as we can't anymore use heap_rlast() on a HASH key entry.
- COLUMN_CREATE(column_nr, value, [column_nr,value]...)
- COLUMN_ADD(blob,column_nr, value, column_nr,value]...)
- COLUMN_DELETE(blob, column_nr, column_nr...)
- COLUMN_EXISTS(blob, column_nr)
- COLUMN_LIST(blob, column_nr)
- COLUMN_GET(string, column_nr AS type)
Added cast(X as DOUBLE) and cast(x as INT)
Better warning and error messages for wrong cast's
Created some sub functions to simplify and reuse code.
Added a lot of conversation functions with error/warnings for what went wrong.
Fixed some issues when casting time to datetime.
Added functions to dynamic strings and Strings to allow one to move a string buffer from dynamic strings to String (to save malloc+ copy)
Added dynamic columns library to libmysqlclient
include/Makefile.am:
Added ma_dyncol.h
include/decimal.h:
Added 'const' to arguments for some functions.
include/my_sys.h:
Added dynstr_reassociate()
include/my_time.h:
Added TIME_SUBSECOND_RANGE
Added double_to_datetime()
Added flag argument to str_to_time()
libmysql/CMakeLists.txt:
Added mysys/ma_dyncol.c
libmysql/Makefile.shared:
Added ma_dyncol
libmysql/libmysql.c:
Added argument to str_to_time()
mysql-test/r/bigint.result:
Better error messages
mysql-test/r/cast.result:
Better warning and error messages
A lot of new cast() tests
mysql-test/r/func_math.result:
Better warning messages
mysql-test/r/func_str.result:
Better warning messages
mysql-test/r/func_time.result:
Better warning messages
mysql-test/r/sp-vars.result:
Better warning messages
mysql-test/r/strict.result:
Better warning messages
New test result
mysql-test/r/type_newdecimal.result:
Better warning messages
mysql-test/r/warnings.result:
Better warning messages
mysql-test/suite/funcs_1/r/innodb_func_view.result:
Updated results after better cast warnings
mysql-test/suite/funcs_1/r/memory_func_view.result:
Updated results after better cast warnings
mysql-test/suite/funcs_1/r/myisam_func_view.result:
Updated results after better cast warnings
mysql-test/suite/optimizer_unfixed_bugs/t/bug43448.test:
Added begin...commit to speed up test.
mysql-test/suite/parts/inc/part_supported_sql_funcs_delete.inc:
Added begin...commit to speed up test.
mysql-test/suite/parts/inc/partition_supported_sql_funcs.inc:
Added begin...commit to speed up test.
mysql-test/suite/parts/r/part_supported_sql_func_innodb.result:
Added begin...commit to speed up test.
mysql-test/suite/parts/r/part_supported_sql_func_myisam.result:
Added begin...commit to speed up test.
mysql-test/suite/parts/r/rpl_partition.result:
Added begin...commit to speed up test.
mysql-test/suite/parts/t/part_supported_sql_func_innodb.test:
Removed duplicated --big_test
mysql-test/suite/parts/t/rpl_partition.test:
Added begin...commit to speed up test.
mysql-test/suite/pbxt/r/cast.result:
Updated results after better cast warnings
mysql-test/suite/pbxt/r/func_str.result:
Updated results after better cast warnings
mysql-test/suite/pbxt/r/type_newdecimal.result:
Updated results after better cast warnings
mysql-test/suite/rpl/r/rpl_innodb_bug28430.result:
Added begin...commit to speed up test.
mysql-test/suite/rpl/t/rpl_innodb_bug28430.test:
Added begin...commit to speed up test.
mysql-test/suite/vcol/r/vcol_supported_sql_funcs_innodb.result:
More warnings
mysql-test/suite/vcol/r/vcol_supported_sql_funcs_myisam.result:
More warnings
mysql-test/t/cast.test:
A lot of new cast() tests
mysql-test/t/strict.test:
Added new test
mysys/CMakeLists.txt:
Added ma_dyncol.c
mysys/Makefile.am:
Added ma_dyncol.c
mysys/string.c:
Added dynstr_reassociate() to move a buffer from dynamic_strings to some other allocator
sql-common/my_time.c:
Added 'fuzzydate' flag to str_to_time()
Added support for microseconds to my_time_to_str() and my_datetime_to_str()
Reset second_parts in number_to_datetime()
Added double_to_datetime()
sql/field.cc:
Added double_to_longlong() and truncate_double() to simplify and reuse code
sql/field.h:
New prototypes
sql/item.cc:
Changed Item::get_date(MYSQL_TIME *ltime,uint fuzzydate) to be aware of type of argument.
(Needed to make it microsecond safe and get better warnings).
Updated call to str_to_time_with_warn()
sql/item.h:
Added struct st_dyncall_create_def used by dynamic columns
Added virtual bool dynamic_result() to tell if type of argument may change over calls.
sql/item_cmpfunc.cc:
Added Item_func_dyncol_exists()
sql/item_cmpfunc.h:
Added class Item_func_dyncol_exists
sql/item_create.cc:
Added get_length_and_scale() to simplify other functions
Simplified and extended create_func_cast()
Added support for cast(X as double(X,Y))
Added functions to create dynamic column functions.
sql/item_create.h:
Added prototypes
sql/item_func.cc:
Extended cast functions Item_func_signed() and Item_func_unsigned() to work with dynamic types
Added Item_double_typecast()
sql/item_func.h:
Added class Item_double_typecast()
sql/item_strfunc.cc:
Added functions for COLUMN_CREATE(), COLUMN_ADD(), COLUMN_GET() and COLUMN_LIST()
sql/item_strfunc.h:
Added classes for COLUMN_CREATE(), COLUMN_ADD(), COLUMN_GET() and COLUMN_LIST()
sql/item_timefunc.cc:
Added flag argument to str_to_time_with_warn()
Updated Item_char_typecast() to handle result type that may change between calls (for dynamic columns)
Added Item_time_typecast::get_date() to ensure that we cast a datetime to time properly.
sql/item_timefunc.h:
Added get_date() to Item_time_typecast() to allow proper results for casting time to datetime
sql/lex.h:
Added new SQL function names
sql/my_decimal.cc:
Added 'const' to some arguments.
Better error message in case of errors (we now print out the wrong value)
Added my_decimal2int()
sql/my_decimal.h:
Moved some constants to my_decimal_limits.h
Updated prototypes.
Made my_decimal2int() a function as it's rather long (no reason to have it inline)
Added decimal2my_decimal() function.
sql/mysql_priv.h:
Prototypes for new functions
sql/share/errmsg.txt:
New error messages for wrong casts and dynamic columns
sql/sql_acl.cc:
Fixed indentation
sql/sql_base.cc:
Added dynamic_column_error_message()
sql/sql_string.h:
Added reassociate() to move a buffer to be owned by String object.
sql/sql_yacc.yy:
Added syntax for COLUMN_ functions.
sql/time.cc:
Updated str_to_datetime_with_warn() flag argument to same type as other functions
Added conversion flag to str_to_time_with_warn() (Similar to all datetime functions)
Added conversion functions with warnings: double_to_datetime_with_warn() and decimal_to_datetime_with_warn()
strings/decimal.c:
Added 'const' to arguments for some functions.
unittest/mysys/Makefile.am:
Added test for dynamic columns code
Changed some String.ptr() -> String.c_ptr() for String that are not guaranteed to end with \0
Removed some c_ptr() usage from parameters to functions that takes ptr & length
Use preallocate buffers to avoid calling malloc() for most operations.
sql/event_db_repository.cc:
alias is now a String
sql/event_scheduler.cc:
c_ptr -> c_ptr_safe() to avoid warnings from valgrind.
sql/events.cc:
c_ptr -> c_ptr_safe() to avoid warnings from valgrind.
c_ptr -> ptr() as function takes ptr & length
sql/field.cc:
alias is now a String
sql/field.h:
alias is now a String
sql/ha_partition.cc:
alias is now a String
sql/handler.cc:
alias is now a String
ptr() -> c_ptr() as string is not guaranteed to be \0 terminated
sql/item.cc:
Store error parameter in separarte buffer to ensure correct error message
sql/item_func.cc:
ptr() -> c_ptr_safe() as string is not guaranteed to be \0 terminated
sql/item_sum.h:
Use my_strtod() instead of my_atof() to not have to make string \0 terminated
sql/lock.cc:
alias is now a String
sql/log.cc:
c_ptr() -> ptr() as function takes ptr & length
sql/log_event.cc:
c_ptr_quick() -> ptr() as we only want to get the pointer to String buffer
sql/opt_range.cc:
ptr() -> c_ptr() as string is not guaranteed to be \0 terminated
sql/opt_table_elimination.cc:
alias is now a String
sql/set_var.cc:
ptr() -> c_ptr() as string is not guaranteed to be \0 terminated
c_ptr() -> c_ptr_safe() to avoid warnings from valgrind.
c_ptr() -> ptr() as function takes ptr & length
Simplify some code.
sql/sp.cc:
c_ptr() -> ptr() as function takes ptr & length
sql/sp_rcontext.cc:
alias is now a String
sql/sql_base.cc:
alias is now a String.
Here we win a realloc() for most alias usage.
sql/sql_class.cc:
Use size descriptor for printf() to avoid accessing bytes outside of buffer
sql/sql_insert.cc:
Change allocation of TABLE as it's now contains a String
_ptr() -> ptr() as function takes ptr & length
sql/sql_load.cc:
Use preallocate buffers to avoid calling malloc() for most operations.
sql/sql_parse.cc:
Use c_ptr_safe() to ensure string is \0 terminated.
sql/sql_plugin.cc:
c_ptr_quick() -> ptr() as function takes ptr & length
sql/sql_select.cc:
alias is now a String
sql/sql_show.cc:
alias is now a String
sql/sql_string.h:
Added move() function to change who owns the string (owner does the free)
sql/sql_table.cc:
alias is now a String
c_ptr() -> c_ptr_safe() to avoid warnings from valgrind.
sql/sql_test.cc:
c_ptr() -> c_ptr_safe() to avoid warnings from valgrind.
alias is now a String
sql/sql_trigger.cc:
c_ptr() -> c_ptr_safe() to avoid warnings from valgrind.
Use field->init() to setup pointers to alias.
sql/sql_update.cc:
alias is now a String
sql/sql_view.cc:
ptr() -> c_ptr_safe() as string is not guaranteed to be \0 terminated
sql/sql_yacc.yy:
r() -> c_ptr() as string is not guaranteed to be \0 terminated
sql/table.cc:
alias is now a String
sql/table.h:
alias is now a String
storage/federatedx/ha_federatedx.cc:
Remove extra 1 byte alloc that is automaticly done by strmake()
Ensure that error message ends with \0
storage/maria/ha_maria.cc:
alias is now a String
storage/myisam/ha_myisam.cc:
alias is now a String
memory reference
There are two issues present here.
1) There is a possibility that we test a byte beyond the
allocated buffer
2) We compare a byte that might never have been
initalized to see if it's 0.
The first issue is not triggered by existing code, but an
ASSERT has been added to safe-guard against introducing
new code that triggers it.
The second issue is what triggers the Valgrind warnings
reported in the bug report. A buffer is allocated in
class String to hold the value. This buffer is populated
by the character data constituting the string, but is not
zero-terminated in most cases. Testing if it is indeed
zero-terminated means that we check a byte that has never
been explicitly set, thus causing Valgrind to trigger.
Note that issue 2 is not a serious problem. The variable
is read, and if it's not zero, we will set it to zero.
There are no further consequences.
Note that this patch does not fix the underlying problems
with issue 1, as it is deemed too risky to fix at this
point (as noted in the bug report). As discussed in
the report, the c_ptr() method should probably be
replaced, but this requires a thorough analysis of the
~200 calls to the method.
sql/set_var.cc:
These two cases have been reported to fail
with Valgrind.
other crashes
Some string manipulating SQL functions use a shared string object intended to
contain an immutable empty string. This object was used by the SQL function
SUBSTRING_INDEX() to return an empty string when one argument was of the wrong
datatype. If the string object was then modified by the sql function INSERT(),
undefined behavior ensued.
Fixed by instead modifying the string object representing the function's
result value whenever string manipulating SQL functions return an empty
string.
Relevant code has also been documented.
- Fixed problem with oqgraph and 'make dist'
Note that after this merge we have a problem show in join_outer where we examine too many rows in one specific case (related to BUG#57024).
This will be fixed when mwl#128 is merged into 5.3.
Open issues:
- A better fix for #57688; Igor is working on this
- Test failure in index_merge_innodb.test ; Igor promised to look at this
- Some Innodb tests fails (need to merge with latest xtradb) ; Kristian promised to look at this.
- Failing tests: innodb_plugin.innodb_bug56143 innodb_plugin.innodb_bug56632 innodb_plugin.innodb_bug56680 innodb_plugin.innodb_bug57255
- Werror is disabled; Should be enabled after merge with xtradb.
- Changed TABLE->alias to String to get fewer reallocs when alias are used.
- Preallocate some buffers
Changed some String->c_ptr() -> String->ptr() when \0 is not needed.
Fixed wrong usage of String->ptr() when we need a \0 terminated string.
Use my_strtod() instead of my_atof() to avoid having to add \0 to string.
c_ptr() -> c_ptr_safe() to avoid warnings from valgrind.
zr
sql/event_db_repository.cc:
Update usage of TABLE->alias
sql/event_scheduler.cc:
c_ptr() -> c_ptr_safe()
sql/events.cc:
c_ptr() -> ptr() as \0 was not needed
sql/field.cc:
Update usage of TABLE->alias
sql/field.h:
Update usage of TABLE->alias
sql/ha_partition.cc:
Update usage of TABLE->alias
sql/handler.cc:
Update usage of TABLE->alias
Fixed wrong usage of str.ptr()
sql/item.cc:
Fixed error where code wrongly assumed string was \0 terminated.
sql/item_func.cc:
c_ptr() -> c_ptr_safe()
Update usage of TABLE->alias
sql/item_sum.h:
Use my_strtod() instead of my_atof() to avoid having to add \0 to string
sql/lock.cc:
Update usage of TABLE->alias
sql/log.cc:
c_ptr() -> ptr() as \0 was not needed
sql/log_event.cc:
c_ptr_quick() -> ptr() as \0 was not needed
sql/opt_range.cc:
ptr() -> c_ptr() as \0 is needed
sql/opt_subselect.cc:
Update usage of TABLE->alias
sql/opt_table_elimination.cc:
Update usage of TABLE->alias
sql/set_var.cc:
ptr() -> c_ptr() as \0 is needed
c_ptr() -> c_ptr_safe()
sql/sp.cc:
c_ptr() -> ptr() as \0 was not needed
sql/sp_rcontext.cc:
Update usage of TABLE->alias
sql/sql_base.cc:
Preallocate buffers
Update usage of TABLE->alias
sql/sql_class.cc:
Fix arguments to sprintf() to work even if string is not \0 terminated
sql/sql_insert.cc:
Update usage of TABLE->alias
c_ptr() -> ptr() as \0 was not needed
sql/sql_load.cc:
Preallocate buffers
Trivial optimizations
sql/sql_parse.cc:
Trivial optimization
sql/sql_plugin.cc:
c_ptr() -> ptr() as \0 was not needed
sql/sql_select.cc:
Update usage of TABLE->alias
sql/sql_show.cc:
Update usage of TABLE->alias
sql/sql_string.h:
Added move() function to move allocated memory from one object to another.
sql/sql_table.cc:
Update usage of TABLE->alias
c_ptr() -> c_ptr_safe()
sql/sql_test.cc:
ptr() -> c_ptr_safe()
sql/sql_trigger.cc:
Update usage of TABLE->alias
c_ptr() -> c_ptr_safe()
sql/sql_update.cc:
Update usage of TABLE->alias
sql/sql_view.cc:
ptr() -> c_ptr_safe()
sql/sql_yacc.yy:
ptr() -> c_ptr()
sql/table.cc:
Update usage of TABLE->alias
sql/table.h:
Changed TABLE->alias to String to get fewer reallocs when alias are used.
storage/federatedx/ha_federatedx.cc:
Use c_ptr_safe() to ensure strings are \0 terminated.
storage/maria/ha_maria.cc:
Update usage of TABLE->alias
storage/myisam/ha_myisam.cc:
Update usage of TABLE->alias
storage/xtradb/row/row0sel.c:
Ensure that null bits in record are properly reset.
(Old code didn't work as row_search_for_mysql() can be called twice while reading fields from one row.
Avoid doing reallocs
Prealloc some strings / provide extension allocation size to some strings
This gave a 25 % speedup in some mysql-test-run tests.
mysys/safemalloc.c:
More DBUG_PRINT
sql/net_serv.cc:
Make all mallocs() look the similar. (just-for-safety fix)
sql/protocol.cc:
Ensure that communication packet buffer is allocated.
(It's freed by stored precedures and some DLL statements)
sql/sp.cc:
Fixed valgrind warning
sql/sql_select.cc:
Set extent allocation for buffer that has a lot of append() calls.
sql/sql_show.cc:
Fixed wrong usage of string buffer. Old code worked in test suite 'just-by-chance'
sql/sql_string.cc:
Call realloc_with_extra_if_needed() in append() functions.
sql/sql_string.h:
Added 'extra_alloc' member, to specify chunck size for realloc().
extra_alloc is addaptive to catch cases where preallocation of buffers is not done properly.
Simplified free() to allow compiler to optimize things better (and to keep things consistent).
Fixed shrink() to take into account the extra memory added to the Alloced_length in realloc(). This saves us a realloc() per query.
sql/sql_test.cc:
Set extent allocation for buffer that has a lot of append() calls.
sql/table.cc:
Set extent allocation for buffer that has a lot of append() calls.
