Commit 5ac0d9360 failed to entirely fix bitshiftright's habit of
leaving one-bits in the pad space that should be all zeroes,
because in a moment of sheer brain fade I'd concluded that only
the code path used for not-a-multiple-of-8 shift distances needed
to be fixed. Of course, a multiple-of-8 shift distance can also
cause the problem, so we need to forcibly zero the extra bits
in both cases.
Per bug #16037 from Alexander Lakhin. As before, back-patch to all
supported branches.
Discussion: https://postgr.es/m/16037-1d1ebca564db54f4@postgresql.org
If the bitstring length is not a multiple of 8, we'd shift the
rightmost bits into the pad space, which must be zeroes --- bit_cmp,
for one, depends on that. This'd lead to the result failing to
compare equal to what it should compare equal to, as reported in
bug #16013 from Daryl Waycott.
This is, if memory serves, not the first such bug in the bitstring
functions. In hopes of making it the last one, do a bit more work
than minimally necessary to fix the bug:
* Add assertion checks to bit_out() and varbit_out() to complain if
they are given incorrectly-padded input. This will improve the
odds that manual testing of any new patch finds problems.
* Encapsulate the padding-related logic in macros to make it
easier to use.
Also, remove unnecessary padding logic from bit_or() and bitxor().
Somebody had already noted that we need not re-pad the result of
bit_and() since the inputs are required to be the same length,
but failed to extrapolate that to the other two.
Also, move a comment block that once was near the head of varbit.c
(but people kept putting other stuff in front of it), to put it in
the header block.
Note for the release notes: if anyone has inconsistent data as a
result of saving the output of bitshiftright() in a table, it's
possible to fix it with something like
UPDATE mytab SET bitcol = ~(~bitcol) WHERE bitcol != ~(~bitcol);
This has been broken since day one, so back-patch to all supported
branches.
Discussion: https://postgr.es/m/16013-c2765b6996aacae9@postgresql.org
bitshiftright() and bitshiftleft() would recursively call each other
infinitely if the user passed INT_MIN for the shift amount, due to integer
overflow in negating the shift amount. To fix, clamp to -VARBITMAXLEN.
That doesn't change the results since any shift distance larger than the
input bit string's length produces an all-zeroes result.
Also fix some places that seemed inadequately paranoid about input typmods
exceeding VARBITMAXLEN. While a typmod accepted by anybit_typmodin() will
certainly be much less than that, at least some of these spots are
reachable with user-chosen integer values.
Andreas Seltenreich and Tom Lane
Discussion: <87d1j2zqtz.fsf@credativ.de>
Several functions, mostly type input functions, calculated an allocation
size such that the calculation wrapped to a small positive value when
arguments implied a sufficiently-large requirement. Writes past the end
of the inadvertent small allocation followed shortly thereafter.
Coverity identified the path_in() vulnerability; code inspection led to
the rest. In passing, add check_stack_depth() to prevent stack overflow
in related functions.
Back-patch to 8.4 (all supported versions). The non-comment hstore
changes touch code that did not exist in 8.4, so that part stops at 9.0.
Noah Misch and Heikki Linnakangas, reviewed by Tom Lane.
Security: CVE-2014-0064
This reduces unnecessary exposure of other headers through htup.h, which
is very widely included by many files.
I have chosen to move the function prototypes to the new file as well,
because that means htup.h no longer needs to include tupdesc.h. In
itself this doesn't have much effect in indirect inclusion of tupdesc.h
throughout the tree, because it's also required by execnodes.h; but it's
something to explore in the future, and it seemed best to do the htup.h
change now while I'm busy with it.
Fix loss of previous expression-simplification work when a transform
function fires: we must not simply revert to untransformed input tree.
Instead build a dummy FuncExpr node to pass to the transform function.
This has the additional advantage of providing a simpler, more uniform
API for transform functions.
Move documentation to a somewhat less buried spot, relocate some
poorly-placed code, be more wary of null constants and invalid typmod
values, add an opr_sanity check on protransform function signatures,
and some other minor cosmetic adjustments.
Note: although this patch touches pg_proc.h, no need for catversion
bump, because the changes are cosmetic and don't actually change the
intended catalog contents.
This enables ALTER TABLE to skip table and index rebuilds when the
new type is unconstraint varbit, or when the allowable number of bits
is not decreasing.
Noah Misch, with review and a fix for an OID collision by me.
This is to avoid use of the C++ keywords "bitand" and "bitor" in
the header file utils/varbit.h. Note the functions' SQL-level
names are not changed, only their C-level names.
In passing, make some comments in varbit.c conform to project-standard
layout.
and implement OVERLAY() for bit strings and bytea.
In passing also convert text OVERLAY() to a true built-in, instead of
relying on a SQL function.
Leonardo F, reviewed by Kevin Grittner
of the string". The previous coding treated only -1 that way, and would
produce an invalid result value for other negative values.
We ought to fix it so that 2-parameter bit substring() is a different C
function and the 3-parameter form throws error for negative length, but
that takes a pg_proc change which is impractical in the back branches;
and in any case somebody might be relying on -1 working this way.
So just do this as a back-patchable fix.
we're not going to support that anymore.
I did keep the 64-bit-CRC-with-32-bit-arithmetic code, since it has a
performance excuse to live. It's a bit moot since that's all ifdef'd
out, of course.
correctly when the output bit width is wider than the given integer by
something other than a multiple of 8 bits.
This has been wrong since I first wrote that code for 8.0 :-(. Kudos to
Roman Kononov for being the first to notice, though I didn't use his
patch. Per bug #5237.
byte after the last full byte of the bit array, regardless of whether that
byte was part of the valid data or not. Found by buildfarm testing.
Thanks to Stefan Kaltenbrunner for nailing down the cause.
an array of strings rather than an array of integers, and allow any simple
constant or identifier to be used in typmods; for example
create table foo (f1 widget(42,'23skidoo',point));
Of course the typmodin function has still got to pack this info into a
non-negative int32 for storage, but it's still a useful improvement in
flexibility, especially considering that you can do nearly anything if you
are willing to keep the info in a side table. We can get away with this
change since we have not yet released a version providing user-definable
typmods. Per discussion.
Get rid of VARATT_SIZE and VARATT_DATA, which were simply redundant with
VARSIZE and VARDATA, and as a consequence almost no code was using the
longer names. Rename the length fields of struct varlena and various
derived structures to catch anyplace that was accessing them directly;
and clean up various places so caught. In itself this patch doesn't
change any behavior at all, but it is necessary infrastructure if we hope
to play any games with the representation of varlena headers.
Greg Stark and Tom Lane
#define HIGHBIT (0x80)
#define IS_HIGHBIT_SET(ch) ((unsigned char)(ch) & HIGHBIT)
and removed CSIGNBIT and mapped it uses to HIGHBIT. I have also added
uses for IS_HIGHBIT_SET where appropriate. This change is
purely for code clarity.
optional arguments as text input functions, ie, typioparam OID and
atttypmod. Make all the datatypes that use typmod enforce it the same
way in typreceive as they do in typinput. This fixes a problem with
failure to enforce length restrictions during COPY FROM BINARY.
Also performed an initial run through of upgrading our Copyright date to
extend to 2005 ... first run here was very simple ... change everything
where: grep 1996-2004 && the word 'Copyright' ... scanned through the
generated list with 'less' first, and after, to make sure that I only
picked up the right entries ...
bigint variants). Clean up some inconsistencies in error message wording.
Fix scanint8 to allow trailing whitespace in INT64_MIN case. Update
int8-exp-three-digits.out, which seems to have been ignored by the last
couple of people to modify the int8 regression test, and remove
int8-exp-three-digits-win32.out which is thereby exposed as redundant.
error code for string-too-long errors. It should be STRING_DATA_RIGHT_TRUNCATION
not STRING_DATA_LENGTH_MISMATCH. The latter probably should only be
applied to cases where a string must be exactly so many bits --- there are
no cases at all where it applies to character strings, only bit strings.
eliminating the former hard-wired convention about their names. Allow
pg_cast entries to represent both type coercion and length coercion in
a single step --- this is represented by a function that takes an
extra typmod argument, just like a length coercion function. This
nicely merges the type and length coercion mechanisms into something
at least a little cleaner than we had before. Make use of the single-
coercion-step behavior to fix integer-to-bit coercion so that coercing
to bit(n) yields the rightmost n bits of the integer instead of the
leftmost n bits. This should fix recurrent complaints about the odd
behavior of this coercion. Clean up the documentation of the bit string
functions, and try to put it where people might actually find it.
Also, get rid of the unreliable heuristics in ruleutils.c about whether
to display nested coercion steps; instead require parse_coerce.c to
label them properly in the first place.
