The fix for BUG#20103 "Escaping with backslash does not work as expected"
was implemented too greedy though in that it not only changes the behavior
of backslashes within strings but in general, so disabling command shortcuts
like \G or \C (which in turn leads to Bug #36391: "mysqlbinlog creates invalid charset
statements").
The fix allows the escaping with backslash to take place only inside a string,
thus enabling the execution of command shortcuts and presevering the fix for
BUG#20103.
Fix parsing of mysql client commands, especially in relation to
single-line comments when --comments was specified.
This is a little tricky, because we need to allow single-line
comments in the middle of statements, but we don't want to allow
client commands in the middle of statements. So in
comment-preservation mode, we go ahead and send single-line
comments to the server immediately when we encounter them on their
own.
This is still slightly flawed, in that it does not handle a
single-line comment with leading spaces, followed by a client-side
command when --comment has been enabled. But this isn't a new
problem, and it is quite an edge condition. Fixing it would require
a more extensive overall of how the mysql client parses commands.
The problem here is that embedded server starts handle_thread manager
thread on mysql_library_init() does not stop it on mysql_library_end().
At shutdown, my_thread_global_end() waits for thread count to become 0,
but since we did not stop the thread it will give up after 5 seconds.
Solution is to move shutdown for handle_manager thread from kill_server()
(mysqld specific) to clean_up() that is used by both embedded and mysqld.
This patch also contains some refactorings - to avoid duplicate code,
start_handle_manager() and stop_handle_manager() functions are introduced.
Unused variables are eliminated. handle_manager does not rely on global
variable abort_loop anymore to stop (abort_loop is not set for embedded).
Note: Specifically on Windows and when using DBUG version of libmysqld,
the complete solution requires removing obsolete code my_thread_init()
from my_thread_var(). This has a side effect that a DBUG statement
after my_thread_end() can cause thread counter to be incremented, and
embedded will hang for some seconds. Or worse, my_thread_init() will
crash if critical sections have been deleted by the global cleanup
routine that runs in a different thread.
This patch also fixes and revert prior changes for Bug#38293
"Libmysqld crash in mysql_library_init if language file missing".
Root cause of the crash observed in Bug#38293 was bug in my_thread_init()
described above
Bug#33812: mysql client incorrectly parsing DELIMITER
Remove unnecessary and incorrect code that tried
to pull delimiter commands out of the middle of
statements.
There was no way to return an error from the client library
if no MYSQL connections was established.
So here i added variables to store that king of errors and
made functions like mysql_error(NULL) to return these.
Nothing was in the command-line dictionary, because of the wrong
order of instructions when populating it.
This is a smaller, less optimistic patch that both fixes a bug and
refreshes the list of keywords that the command-line library (e.g.,
readline) can use to expand typed commands. Now, read from the
command list /after/ we free the list, not before.
The best way is to read the keywords from the lexer code, but that
doesn't work everywhere yet. Grr.
running queries
Bug#33976: buffer overflow of variable time_buff in function com_go()
An internal buffer was too short. Overextending could smash the
stack on some architectures and cause SEGVs. This is not a problem
that could be exploited to run arbitrary code.
To fix, I expanded one buffer to cover all the size that could be
written to (we know the abolute max).
Default values of variables were not subject to upper/lower bounds
and step, while setting variables was. Bounds and step are also
applied to defaults now; defaults are corrected quietly, values
given by the user are corrected, and a correction-warning is thrown
as needed. Lastly, very large values could wrap around, starting
from 0 again. They are bounded at the maximum value for the
respective data-type now if no lower maximum is specified in the
variable's definition.
In several cases, an error when processing the query would cause mysql to
return to the top level without printing warnings. Fix is to always
print any available warnings before returning to the top level.
