to the use of getpwuid when running in standalone mode.
this patch allocates some persistent storage (using
strdup) to store the username obtained with getpwuid
in src/backend/main/main.c.  this is necessary because
later on, getpwuid is called again (in ValidateBinary).

the man pages for getpwuid on SCO OpenServer, FreeBSD,
and Darwin all have words to this effect (this is from
the SCO OpenServer man page):

  Note
  ====
  All information is contained in a static area, so it must
  be copied if it is to be saved. Otherwise, it may be
  overwritten on subsequent calls to these routines.

in particular, on my platform, the storage used to hold
the pw_name from the first call is overwritten such that
it looks like an empty username.  this causes a problem
later on in SetSessionUserIdFromUserName.

i'd assume this isn't a problem on most platforms because
getpwuid is called with the same UID both times, and the
same thing ends up happening to that static storage each
time.  however, that's not guaranteed, and is _not_ what
happens on my platform (at least :).

this is for the version of 7.1 available via anon cvs as
of Tue Jan 23 15:14:00 2001 PST:
  .../src/backend/main/main.c,v 1.37 2000/12/31 18:04:35 tgl Exp

-michael thornburgh, zenomt@armory.com

timing, I know :))  At the moment the digest() function returns
hexadecimal coded hash, but I want it to return pure binary.  I
have also included functions encode() and decode() which support
'base64' and 'hex' encodings, so if anyone needs digest() in hex
he can do encode(digest(...), 'hex').

Main reason for it is "to do one thing and do it well" :)

Another reason is if someone needs really lot of digesting, in
the end he wants to store the binary not the hexadecimal result.
It is really silly to convert it to hex then back to binary
again.  As I said if someone needs hex he can get it.

Well, and the real reason that I am doing encrypt()/decrypt()
functions and _they_ return binary.  For testing I like to see
it in hex occasionally, but it is really wrong to let them
return hex.  Only now it caught my eye that hex-coding in
digest() is wrong.  When doing digest() I thought about 'common
case' but hacking with psql is probably _not_ the common case :)

Marko Kreen

and psql) again. Changes are:
1) psql requires the includes of "io.h" and "fcntl.h" in command.c in order
to make a call to open() work (io.h for _open(), fcntl.h for the O_xxx)
2) PG_VERSION is no longer defined in version.h[.in], but in configure.in.
Since we don't do configure on native win32, we need to put it in
config.h.win32 :-(
3) Added define of SYSCONFDIR to config.h.win32 - libpq won't compile
without it. This functionality is *NOT* tested - it's just defined as "" for
now. May work, may not.
4) DEF_PGPORT renamed to DEF_PGPORT_STR

I have done the "basic tests" on it - it connects to a database, and I can
run queries. Haven't tested any of the fancier functions (yet).

However, I stepped on a much bigger problem when fixing psql to work. It no
longer works when linked against the .DLL version of libpq (which the
Makefile does for it). I have left it linked against this version anyway,
pending the comments I get on this mail :-)
The problem is that there are strings being allocated from libpq.dll using
PQExpBuffers (for example, initPQExpBuffer() on line 92 of input.c). These
are being allocated using the malloc function used by libpq.dll. This
function *may* be different from the malloc function used by psql.exe - only
the resulting pointer must be valid. And with the default linking methods,
it *WILL* be different. Later, psql.exe tries to free() this string, at
which point it crashes because the free() function can't find the allocated
block (it's on the allocated blocks list used by the runtime lib of
libpq.dll).

Shouldn't the right thing to do be to have psql call termPQExpBuffer() on
the data instead? As it is now, gets_fromFile() will just return the pointer
received from the PQExpBuffer.data (this may well be present at several
places - this is the one I was bitten by so far). Isn't that kind of
"accessing the internals of the PQExpBuffer structure" wrong? Instead,
perhaps it shuold make a copy of the string, adn then termPQExpBuffer() it?
In that case, the string will have been allocated from within the same
library as the free() is called.

I can get it to work just fine by doing this - changing from (around line
100 of input.c):
and the same a bit further down in the same function.

But, as I said above, this may be at more places in the code? Perhaps
someone more familiar to it could comment on that?


What do you think shuld be done about this? Personally, I go by the "If you
allocate a piece of memory using an interface, use the same interface to
free it", but the question is how to make it work :-)


Also, AFAIK this only affects psql.exe, so the changes made to the libpq
this patch are required no matter how the other issue is handled.

Regards,
 Magnus

than forcing 'plain'.  This probably does not matter right now, but I
think it needs to be consistent with the regular (not-functional) index
case, where attstorage is copied from the underlying table.  Clean up
some other dead and infelicitous code too.

Op, so that the sequence 'a_expr Op Op a_expr' will be parsed as
a_expr Op (Op a_expr) not (a_expr Op) Op a_expr as formerly.  In other
words, prefer treating user-defined operators as prefix operators to
treating them as postfix operators, when there is an ambiguity.
Also clean up a couple of other infelicities in production priority
assignment --- for example, BETWEEN wasn't being given the intended
priority, but that of AND.

Query used for checking foreign key triggers
returns too many results when there're more than one foreign
key in a table. It happens because only table's oid is used to
link between pg_trigger with INSERT check and pg_trigger with
UPDATE/DELETE check.

I think there should be enough to add following conditions
into WHERE clause of that query:
        AND     pt.tgconstrname = pg_trigger.tgconstrname
        AND     pt.tgconstrname = pg_trigger_1.tgconstrname

/Constantin

bothering to check the return value --- which meant that in case the
update or delete failed because of a concurrent update, you'd not find
out about it, except by observing later that the transaction produced
the wrong outcome.  There are now subroutines simple_heap_update and
simple_heap_delete that should be used anyplace that you're not prepared
to do the full nine yards of coping with concurrent updates.  In
practice, that seems to mean absolutely everywhere but the executor,
because *noplace* else was checking.

attributes in a FieldSelect node --- all the places that manipulate
these work just fine with system attribute numbers.  OK, it's a new
feature, so shoot me ...

at end of its block, maybe we can enlarge it in-place.

into new chapter on query (SELECT) syntax.  In the end this should become
a narrative and example-filled counterpart to the SELECT reference page.

eliminates a raft of portability issues, including whether sys_nerr
exists, whether the platform has any valid negative errnos, etc.  The
downside is minimal: errno shouldn't ever contain an invalid value anyway,
and if it does, reasonably modern versions of strerror will not choke.
This rangecheck idea seemed good at the time, but it's clearly a net loss,
and I apologize to all concerned for having ever put it in.