strict aliasing violations.
Essentially, the problem is that large parts of the server were
developed in simpler times (last decades, pre C99 standard) when
strict aliasing and compilers supporting such optimizations were
rare to non-existent. Thus, when compiling the server with a modern
compiler that uses strict aliasing rules to perform optimizations,
there are several places in the code that might trigger undefined
behavior.
As evinced by some recent bugs, GCC does a somewhat good of job
misoptimizing such code, but on the other hand also gives warnings
about suspicious code. One problem is that the warnings aren't
always accurate, yet we can't afford to just shut them off as we
might miss real cases. False-positive cases are aggravated mostly
by casts that are likely to trigger undefined behavior.
The solution is to start a cleanup process focused on fixing and
reducing the amount of strict-aliasing related warnings produced
by GCC and others compilers. A good deal of noise reduction can
be achieved by just removing useless casts that are product of
historical cruft and are likely to trigger undefined behavior if
dereferenced.
Several items said to be deprecated in the 4.1 manual
have never been removed. This worklog adds deprecation
warnings when these items are used, and warns the user
that the items will be removed in MySQL 5.6.
A couple of previously deprecation decision have been
reversed (see single file comments)
The problem is a somewhat common misusage of the strmake function.
The strmake(dst, src, len) function writes at most /len/ bytes to
the string pointed to by src, not including the trailing null byte.
Hence, if /len/ is the exact length of the destination buffer, a
one byte buffer overflow can occur if the length of the source
string is equal to or greater than /len/.
when used with --tab
1) New syntax: added CHARACTER SET clause to the
SELECT ... INTO OUTFILE (to complement the same clause in
LOAD DATA INFILE).
mysqldump is updated to use this in --tab mode.
2) ESCAPED BY/ENCLOSED BY field parameters are documented as
accepting CHAR argument, however SELECT .. INTO OUTFILE
silently ignored rests of multisymbol arguments.
For the symmetrical behavior with LOAD DATA INFILE the
server has been modified to fail with the same error:
ERROR 42000: Field separator argument is not what is
expected; check the manual
3) Current LOAD DATA INFILE recognizes field/line separators
"as is" without converting from client charset to data
file charset. So, it is supposed, that input file of
LOAD DATA INFILE consists of data in one charset and
separators in other charset. For the compatibility with
that [buggy] behaviour SELECT INTO OUTFILE implementation
has been saved "as is" too, but the new warning message
has been added:
Non-ASCII separator arguments are not fully supported
This message warns on field/line separators that contain
non-ASCII symbols.
mysqldump --tab still dumped triggers to stdout rather than to
individual tables.
We now append triggers to the .sql file for the corresponding
table.
--events and --routines correspond to a database rather than a
table and will still go to stdout with --tab unless redirected
with --result-file (-r).
When loading dump created by mysqldump tool an error is
thrown saying storage engine for the table doesn't have
an option.
mysqldump tries to re-insert the data into the federated
table which causes the error. Since the data is already
available on the remote server, mysqldump shouldn't try
to dump the data again for FEDERATED tables.
As stated in the bug page, it can be considered similar
to the MERGE ENGINE with "view only" nature.
Fixed by adding the "FEDERATED ENGINE" to the exception
list to ignore the data.
--ignore-table option
mysqldump would correctly omit temporary tables for views, but would
incorrectly still emit all CREATE VIEW statements.
Backport a fix from 5.1, where we capture the names we want to emit
views for in one pass (the placeholder tables) and in the pass where
we actually emit the views, we don't emit a view if it wasn't in that
list.
- Remove bothersome warning messages. This change focuses on the warnings
that are covered by the ignore file: support-files/compiler_warnings.supp.
- Strings are guaranteed to be max uint in length
- Remove bothersome warning messages. This change focuses on the warnings
that are covered by the ignore file: support-files/compiler_warnings.supp.
- Strings are guaranteed to be max uint in length
mysqldump included character_set_client magic
that is unknown before 4.1 even when asked for
an appropriate compatibility mode.
In compatibility (3.23, 4.0) mode, we do not
output charset statements (not even in a
"comment conditional"), nor do we do magic on
the server, even if the server is sufficient
new (4.1+). Table-names will be output converted
to the charset requested by mysqldump; if such
a conversion is not possible (Ivrit -> Latin),
mysqldump will fail.
mysqldump creates stand-in tables before dumping the actual view.
Those tables were of the default type; if the view had more columns
than that (a pathological case, arguably), loading the dump would
fail. We now make the temporary stand-ins MyISAM tables to prevent
this.
mysqldump creates stand-in tables before dumping the actual view.
Those tables were of the default type; if the view had more columns
than that (a pathological case, arguably), loading the dump would
fail. We now make the temporary stand-ins MyISAM tables to prevent
this.
when --master-data is used
When using the --master-data option with mysqldump, mysqldump uses
a FLUSH TABLES command. However, this statement got replicated to
the slave(s), which caused the slave(s) to block unnecessarily while
the FLUSH tables command completed.
Now, if the master-data option is set to one of the two "on" modes,
then use the "LOCAL" qualifier to ensure that it's not replicated.
