pg_base64_enc_len() and its clones overestimated the output
length by up to 2 bytes, as a result of sloppy thinking about
where to divide. No callers require a precise estimate, so
this has no consequences worse than palloc'ing a byte or two
more than necessary. We might as well get it right though.
This bug is very ancient, dating to commit 79d78bb26 which
added encode.c. (The other instances were presumably copied
from there.) Still, it doesn't quite seem worth back-patching.
Oleg Tselebrovskiy
Discussion: https://postgr.es/m/f94da55286a63022150bc266afdab754@postgrespro.ru
The PostgreSQL contrib tree
---------------------------
This subtree contains porting tools, analysis utilities, and plug-in
features that are not part of the core PostgreSQL system, mainly
because they address a limited audience or are too experimental to be
part of the main source tree. This does not preclude their
usefulness.
User documentation for each module appears in the main SGML
documentation.
When building from the source distribution, these modules are not
built automatically, unless you build the "world" target. You can
also build and install them all by running "make all" and "make
install" in this directory; or to build and install just one selected
module, do the same in that module's subdirectory.
Some directories supply new user-defined functions, operators, or
types. To make use of one of these modules, after you have installed
the code you need to register the new SQL objects in the database
system by executing a CREATE EXTENSION command. In a fresh database,
you can simply do
CREATE EXTENSION module_name;
See the PostgreSQL documentation for more information about this
procedure.