IdoPgsqlConnection::Escape() internally uses PQescapeStringConn() and its
documentation states the following:
Furthermore, PQescapeStringConn does not generate the single quotes that must
surround PostgreSQL string literals; they should be provided in the SQL
command that the result is inserted into.
So it's intended to use the result in 'string' literals, not in E'string'
literals as Icinga did. This results in problems as the behavior of
PQescapeStringConn() depends on how the current connection will interpret
regular single quoted literals, namely on the value of the
standard_conforming_strings variable.
The E'string' literals were initially introduced in
ac6f3f8acf4f52adedc7908db6452ed6da273ad7 to fix#1206 where PostgreSQL started
warning about escape sequences in string literals not supported by the SQL
standard (but by PostgreSQL depending on the value of
standard_conforming_strings). In the meantime the oldest PostgreSQL version on
any platform supported by Icinga increased to 9.2 (CentOS 7) and starting with
9.1, standard_conforming_strings is enabled by default, so there will be no
warnings about escape sequences (as the warning is only issued if the escape
sequence is actually interpreted by PostgreSQL).
Icinga started the initial config sync right after the first Redis connection
was established. If any other connections would take longer to connect than
when it's first needed, queries were discarded.
The loop in the connected callback of the parent connection uses m_Rcons which
previously was only initialized after that connection was already started.
This allows the callback to call RedisConnection::SetConnectedCallback() to set
another callback for this connection. This sets m_ConnectedCallback and thereby
destroys the std::function while it's running resulting in undefined behavior.
By operating on a copy, m_ConnectedCallback can be set without affecting the
currently running callback.
As Icinga first sends a SIGTERM to a check plugin on timeout to allow it to
terminate gracefully, this is not really part of the plugin API specification
and we cannot assume that plugins will handle this correctly and still exit
with an exit code that maps to UNKNOWN. Therefore, once Icinga decides to kill
a process, force its exit code to 128 to be sure the state will be UNKNOWN
after a timeout.
I.e. do the following in parallel (highest priority first):
* Stream state changes to icinga:runtime:state
* Sync config and initial state,
then let queued runtime updates to the just synced state pass
Many functions of LegacyTimePeriod take a tm pointer as an input parameter and
then pass it to mktime() which actually modifies it. This causes problems if
tm_isdst was intentionally set to -1 (to automatically detect whether DST is
active at some time) and then a function is called that implicitly sets
tm_isdst and then the values of tm are modified in a way that crosses a DST
change. This resulted in 1 hour offsets with ScheduledDowntimes on days with
DST changes.
