There were many PG_GETARG_* calls, mostly around gin, gist, spgist
code, that were commented out, presumably to indicate that the
argument was unused and to indicate that it wasn't forgotten or
miscounted. But keeping commented-out code updated with refactorings
and style changes is annoying. So this commit changes them to
#ifdef NOT_USED
blocks, which is a style already in use. That way, at least the
indentation and syntax highlighting works correctly, making some of
these blocks much easier to read.
An alternative would be to just delete that code, but there is some
value in making unused arguments explicit, and some of this arguably
serves as example code for index AM APIs.
Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi>
Reviewed-by: David Geier <geidav.pg@gmail.com>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Reviewed-by: Dean Rasheed <dean.a.rasheed@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/328e4371-9a4c-4196-9df9-1f23afc900df%40eisentraut.org
Liujinyang reported the one in binaryheap.c, I then found and analyzed
the rest.
For future patches, we require git archaelogical analysis before we
accept patches of this nature.
Co-authored-by: liujinyang <21043272@qq.com>
Co-authored-by: Álvaro Herrera <alvherre@kurilemu.de>
Discussion: https://postgr.es/m/tencent_6B302BFCAF6F010E00AB5C2C0ECB7AA3F205@qq.com
This change is a cocktail of harmonization of function argument names,
grammar typos, renames for better consistency and unused code (see
ltree). All of these have been spotted by the author.
Author: Alexander Lakhin <exclusion@gmail.com>
Discussion: https://postgr.es/m/b2c0d0b7-3944-487d-a03d-d155851958ff@gmail.com
Previously, ltree_prefix_eq_ci() used lowercasing with the default
collation; while ltree_crc32_sz() used tolower() directly. These were
equivalent only if the default collation provider was libc and the
encoding was single-byte.
Change both to use casefolding with the default collation.
Backpatch through 18, where the casefolding APIs were introduced. The
bug exists in earlier versions, but would require some adaptation.
A REINDEX is required for ltree indexes where the database default
collation is not libc.
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Backpatch-through: 18
Discussion: https://postgr.es/m/450ceb6260cad30d7afdf155d991a9caafee7c0d.camel@j-davis.com
Discussion: https://postgr.es/m/01fc00fd66f641b9693d4f9f1af0ccf44cbdfbdf.camel@j-davis.com
Previously, the API for ltree_strncasecmp() took two inputs but only
one length (that of the smaller input). It truncated the larger input
to that length, but that could break a multibyte sequence.
Change the API to be a check for prefix equality (possibly
case-insensitive) instead, which is all that's needed by the
callers. Also, provide the lengths of both inputs.
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Discussion: https://postgr.es/m/5f65b85740197ba6249ea507cddf609f84a6188b.camel%40j-davis.com
Backpatch-through: 14
The idea is to encourage more the use of these new routines across the
tree, as these offer stronger type safety guarantees than palloc(). In
an ideal world, palloc() would then act as an internal routine of these
flavors, whose footprint in the tree is minimal.
The patch sent by the author is very large, and this chunk of changes
represents something like 10% of the overall patch submitted.
The code compiled is the same before and after this commit, using
objdump to do some validation with a difference taken in-between. There
are some diffs, which are caused by changes in line numbers because some
of the new allocation formulas are shorter, for the following files:
trgm_regexp.c, xpath.c and pg_walinspect.c.
Author: David Geier <geidav.pg@gmail.com>
Discussion: https://postgr.es/m/ad0748d4-3080-436e-b0bc-ac8f86a3466a@gmail.com
subpath(ltree,offset,len) now correctly errors when given an offset
less than -n, where n is the number of labels in the given ltree.
There was a duplicate block of code that allowed an offset as low
as -2n. The documentation says no such thing, so this must have
been a copy-and-paste error in the original ltree patch.
While here, avoid redundant calculation of "end" and write
LTREE_MAX_LEVELS rather than its hard-coded value.
Author: Marcus Gartner <m.a.gartner@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CAAUGV_SvBO9gWYbaejb9nhe-mS9FkNP4QADNTdM3wdRhvLobwA@mail.gmail.com
Fix a couple more places where an explicit Datum conversion
is needed (not clear how we missed these in ff89e182d and
previous commits).
Replace the minority usage "(Datum) NULL" with "(Datum) 0".
The former depends on the assumption that Datum is the same
width as Pointer, the latter doesn't. Anyway consistency
is a good thing.
This is, I believe, the last of the notational mop-up needed
before we can consider changing Datum to uint64 everywhere.
It's also important cleanup for more aggressive ideas such
as making Datum a struct.
Discussion: https://postgr.es/m/1749799.1752797397@sss.pgh.pa.us
Discussion: https://postgr.es/m/8246d7ff-f4b7-4363-913e-827dadfeb145@eisentraut.org
It seems potentially useful to label our shared libraries with version
information, now that a facility exists for retrieving that. This
patch labels them with the PG_VERSION string. There was some
discussion about using semantic versioning conventions, but that
doesn't seem terribly helpful for modules with no SQL-level presence;
and for those that do have SQL objects, we typically expect them
to support multiple revisions of the SQL definitions, so it'd still
not be very helpful.
I did not label any of src/test/modules/. It seems unnecessary since
we don't install those, and besides there ought to be someplace that
still provides test coverage for the original PG_MODULE_MAGIC macro.
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/dd4d1b59-d0fe-49d5-b28f-1e463b68fa32@gmail.com
These do the same thing as the standard isdigit(), isspace(), and
isprint() but with multibyte and encoding support. But all the
callers are only interested in analyzing single-byte ASCII characters.
So this extra layer is overkill and we can replace the uses with the
standard functions.
All the t_is*() functions in ts_locale.c are under scrutiny because
they don't use the common locale provider framework but instead use
the global libc locale settings. For the functions being touched by
this patch, we don't need all that anyway, as mentioned above, so the
simplest solution is to just remove them. The few remaining t_is*()
functions will need a different treatment in a separate patch.
pg_trgm has some compile-time options with macros such as
KEEPONLYALNUM. These are not documented, and the non-default variant
is not supported by any test cases. As part of this undertaking, I'm
removing the non-default variant, as it is in the way of cleanup. So
in this case, the not-KEEPONLYALNUM code path is gone.
Reviewed-by: Jeff Davis <pgsql@j-davis.com>
Discussion: https://www.postgresql.org/message-id/flat/653f3b84-fc87-45a7-9a0c-bfb4fcab3e7d%40eisentraut.org
Run pgindent, pgperltidy, and reformat-dat-files.
This set of diffs is a bit larger than typical. We've updated to
pg_bsd_indent 2.1.2, which properly indents variable declarations that
have multi-line initialization expressions (the continuation lines are
now indented one tab stop). We've also updated to perltidy version
20230309 and changed some of its settings, which reduces its desire to
add whitespace to lines to make assignments etc. line up. Going
forward, that should make for fewer random-seeming changes to existing
code.
Discussion: https://postgr.es/m/20230428092545.qfb3y5wcu4cm75ur@alvherre.pgsql
Unaligned siglen could lead to an unaligned access to subsequent key fields.
Backpatch to 13, where opclass options were introduced.
Reported-by: Alexander Lakhin
Bug: 17847
Discussion: https://postgr.es/m/17847-171232970bea406b%40postgresql.org
Reviewed-by: Tom Lane, Pavel Borisov, Alexander Lakhin
Backpatch-through: 13
pg_input_error_info() is now a SQL function able to return a row with
more than just the error message generated for incorrect data type
inputs when these are able to handle soft failures, returning more
contents of ErrorData, as of:
- The error message (same as before).
- The error detail, if set.
- The error hint, if set.
- SQL error code.
All the regression tests that relied on pg_input_error_message() are
updated to reflect the effects of the rename.
Per discussion with Tom Lane and Andrew Dunstan.
Author: Nathan Bossart
Discussion: https://postgr.es/m/139a68e1-bd1f-a9a7-b5fe-0be9845c6311@dunslane.net
We chose a specific wording of the not-implemented errors for
pseudotype I/O functions and other cases where there's little
value in implementing input and/or output. gtsvectorin never
got that memo though, nor did most of contrib. Make these all
fall in line, mostly because I'm a neatnik but also to remove
unnecessary translatable strings.
gbtreekey_in needs a bit of extra love since it supports
multiple SQL types. Sadly, gbtreekey_out doesn't have the
ability to do that, but I think it's unreachable anyway.
Noted while surveying datatype input functions to see what we
have left to fix.
The t_iseq() macro does not need to be guarded by a character
length check (at least when the comparison value is an ASCII
character, as its documentation requires). Some portions of
contrib/ltree hadn't read that memo, so simplify them.
The last change in gettoken_query,
- else if (charlen == 1 && !t_iseq(state->buf, ' '))
+ else if (!t_iseq(state->buf, ' '))
looks like it's actually a bug fix: I doubt that the intention
was to silently ignore multibyte characters as if they were
whitespace. I'm not tempted to back-patch though, because this
will have the effect of tightening what is allowed in ltxtquery
strings.
Discussion: https://postgr.es/m/2548310.1664999615@sss.pgh.pa.us
ts_locale.c omitted support for "isalnum" tests, perhaps on the
grounds that there were initially no use-cases for that. However,
both ltree and pg_trgm need such tests, and we do also have one
use-case now in the core backend. The workaround of testing
isalpha and isdigit separately seems quite inefficient, especially
when dealing with multibyte characters; so let's fill in the
missing support.
Discussion: https://postgr.es/m/2548310.1664999615@sss.pgh.pa.us
The generated resource files aren't exactly the same ones as the old
buildsystems generate. Previously "InternalName" and "OriginalFileName" were
mostly wrong / not set (despite being required), but that was hard to fix in
at least the make build. Additionally, the meson build falls back to a
"auto-generated" description when not set, and doesn't set it in a few cases -
unlikely that anybody looks at these descriptions in detail.
Author: Andres Freund <andres@anarazel.de>
Author: Nazir Bilal Yavuz <byavuz81@gmail.com>
Reviewed-by: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Make sure that function declarations use names that exactly match the
corresponding names from function definitions in contrib code.
Like other recent commits that cleaned up function parameter names, this
commit was written with help from clang-tidy.
Author: Peter Geoghegan <pg@bowt.ie>
Discussion: https://postgr.es/m/CAH2-WznJt9CMM9KJTMjJh_zbL5hD9oX44qdJ4aqZtjFi-zA3Tg@mail.gmail.com
Autoconf is showing its age, fewer and fewer contributors know how to wrangle
it. Recursive make has a lot of hard to resolve dependency issues and slow
incremental rebuilds. Our home-grown MSVC build system is hard to maintain for
developers not using Windows and runs tests serially. While these and other
issues could individually be addressed with incremental improvements, together
they seem best addressed by moving to a more modern build system.
After evaluating different build system choices, we chose to use meson, to a
good degree based on the adoption by other open source projects.
We decided that it's more realistic to commit a relatively early version of
the new build system and mature it in tree.
This commit adds an initial version of a meson based build system. It supports
building postgres on at least AIX, FreeBSD, Linux, macOS, NetBSD, OpenBSD,
Solaris and Windows (however only gcc is supported on aix, solaris). For
Windows/MSVC postgres can now be built with ninja (faster, particularly for
incremental builds) and msbuild (supporting the visual studio GUI, but
building slower).
Several aspects (e.g. Windows rc file generation, PGXS compatibility, LLVM
bitcode generation, documentation adjustments) are done in subsequent commits
requiring further review. Other aspects (e.g. not installing test-only
extensions) are not yet addressed.
When building on Windows with msbuild, builds are slower when using a visual
studio version older than 2019, because those versions do not support
MultiToolTask, required by meson for intra-target parallelism.
The plan is to remove the MSVC specific build system in src/tools/msvc soon
after reaching feature parity. However, we're not planning to remove the
autoconf/make build system in the near future. Likely we're going to keep at
least the parts required for PGXS to keep working around until all supported
versions build with meson.
Some initial help for postgres developers is at
https://wiki.postgresql.org/wiki/Meson
With contributions from Thomas Munro, John Naylor, Stone Tickle and others.
Author: Andres Freund <andres@anarazel.de>
Author: Nazir Bilal Yavuz <byavuz81@gmail.com>
Author: Peter Eisentraut <peter@eisentraut.org>
Reviewed-By: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Discussion: https://postgr.es/m/20211012083721.hvixq4pnh2pixr3j@alap3.anarazel.de
guc.c has grown to be one of our largest .c files, making it
a bottleneck for compilation. It's also acquired a bunch of
knowledge that'd be better kept elsewhere, because of our not
very good habit of putting variable-specific check hooks here.
Hence, split it up along these lines:
* guc.c itself retains just the core GUC housekeeping mechanisms.
* New file guc_funcs.c contains the SET/SHOW interfaces and some
SQL-accessible functions for GUC manipulation.
* New file guc_tables.c contains the data arrays that define the
built-in GUC variables, along with some already-exported constant
tables.
* GUC check/assign/show hook functions are moved to the variable's
home module, whenever that's clearly identifiable. A few hard-
to-classify hooks ended up in commands/variable.c, which was
already a home for miscellaneous GUC hook functions.
To avoid cluttering a lot more header files with #include "guc.h",
I also invented a new header file utils/guc_hooks.h and put all
the GUC hook functions' declarations there, regardless of their
originating module. That allowed removal of #include "guc.h"
from some existing headers. The fallout from that (hopefully
all caught here) demonstrates clearly why such inclusions are
best minimized: there are a lot of files that, for example,
were getting array.h at two or more levels of remove, despite
not having any connection at all to GUCs in themselves.
There is some very minor code beautification here, such as
renaming a couple of inconsistently-named hook functions
and improving some comments. But mostly this just moves
code from point A to point B and deals with the ensuing
needs for #include adjustments and exporting a few functions
that previously weren't exported.
Patch by me, per a suggestion from Andres Freund; thanks also
to Michael Paquier for the idea to invent guc_funcs.c.
Discussion: https://postgr.es/m/587607.1662836699@sss.pgh.pa.us
This is in preparation for defaulting to -fvisibility=hidden in extensions,
instead of relying on all symbols in extensions to be exported.
This should have been committed before 089480c077, but something in my commit
scripts went wrong.
Author: Andres Freund <andres@anarazel.de>
Reviewed-By: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/20211101020311.av6hphdl6xbjbuif@alap3.anarazel.de
MemSet() with a value other than 0 just falls back to memset(), so the
indirection is unnecessary if the value is constant and not 0. Since
there is some interest in getting rid of MemSet(), this gets some easy
cases out of the way. (There are a few MemSet() calls that I didn't
change to maintain the consistency with their surrounding code.)
Discussion: https://www.postgresql.org/message-id/flat/CAEudQApCeq4JjW1BdnwU=m=-DvG5WyUik0Yfn3p6UNphiHjj+w@mail.gmail.com
911e702077 implemented operator class parameters including the signature length
in ltree. Previously, the signature length for gist_ltree_ops was 8. Because
of bug 911e702077 the default signature length for gist_ltree_ops became 28 for
ltree 1.1 (where options method is NOT provided) and 8 for ltree 1.2 (where
options method is provided). This commit changes the default signature length
for ltree 1.1 to 8.
Existing gist_ltree_ops indexes might be corrupted in various scenarios.
Thus, we have to recommend reindexing all the gist_ltree_ops indexes after
the upgrade.
Reported-by: Victor Yegorov
Reviewed-by: Tomas Vondra, Tom Lane, Andres Freund, Nikita Glukhov
Reviewed-by: Andrew Dunstan
Author: Tomas Vondra, Alexander Korotkov
Discussion: https://postgr.es/m/17406-71e02820ae79bb40%40postgresql.org
Discussion: https://postgr.es/m/d80e0a55-6c3e-5b26-53e3-3c4f973f737c%40enterprisedb.com
All the code paths simplified here were already using a boolean or used
an expression that led to zero or one, making the extra bits
unnecessary.
Author: Justin Pryzby
Reviewed-by: Tom Lane, Michael Paquier, Peter Smith
Discussion: https://postgr.es/m/20210428182936.GE27406@telsasoft.com
This adjusts the MSVC build scripts to look at the compile flags mentioned
in the Makefile to look for -D arguments in order to determine which
constants should be defined in Visual Studio builds.
One small anomaly that appeared as a result of this change is that the
Makefile for the ltree contrib module defined LOWER_NODE, but this was
not properly defined in the MSVC build scripts. This meant that MSVC
builds would differ in case sensitivity in the ltree module when
compared to builds using a make build environment. To maintain the same
behavior here we remove the -DLOWER_NODE from the Makefile and just always
define it in ltree.h for non-MSVC builds. We need to maintain the old
behavior here as this affects the on-disk compatibility of GiST indexes
when using the ltree type.
The only other resulting change here is that REFINT_VERBOSE is now defined
for the autoinc, insert_username and moddatetime contrib modules.
Previously on MSVC, this was only defined for the refint module. This
aligns the behavior to build environments using make as all 4 of these
modules share the same Makefile.
Reviewed-by: Tom Lane
Discussion: https://postgr.es/m/CAApHDvpo6g5csCTjc_0C7DMvgFPomVb0Rh-AcW5afd=Ya=LRuw@mail.gmail.com
Hostile objects located within the installation-time search_path could
capture references in an extension's installation or upgrade script.
If the extension is being installed with superuser privileges, this
opens the door to privilege escalation. While such hazards have existed
all along, their urgency increases with the v13 "trusted extensions"
feature, because that lets a non-superuser control the installation path
for a superuser-privileged script. Therefore, make a number of changes
to make such situations more secure:
* Tweak the construction of the installation-time search_path to ensure
that references to objects in pg_catalog can't be subverted; and
explicitly add pg_temp to the end of the path to prevent attacks using
temporary objects.
* Disable check_function_bodies within installation/upgrade scripts,
so that any security gaps in SQL-language or PL-language function bodies
cannot create a risk of unwanted installation-time code execution.
* Adjust lookup of type input/receive functions and join estimator
functions to complain if there are multiple candidate functions. This
prevents capture of references to functions whose signature is not the
first one checked; and it's arguably more user-friendly anyway.
* Modify various contrib upgrade scripts to ensure that catalog
modification queries are executed with secure search paths. (These
are in-place modifications with no extension version changes, since
it is the update process itself that is at issue, not the end result.)
Extensions that depend on other extensions cannot be made fully secure
by these methods alone; therefore, revert the "trusted" marking that
commit eb67623c9 applied to earthdistance and hstore_plperl, pending
some better solution to that set of issues.
Also add documentation around these issues, to help extension authors
write secure installation scripts.
Patch by me, following an observation by Andres Freund; thanks
to Noah Misch for review.
Security: CVE-2020-14350
Commit 5e0928005 changed the planner so that, instead of blindly using
DEFAULT_COLLATION_OID when invoking operators for selectivity estimation,
it would use the collation of the column whose statistics we're
considering. This was recognized as still being not quite the right
thing, but it seemed like a good incremental improvement. However,
shortly thereafter we introduced nondeterministic collations, and that
creates cases where operators can fail if they're passed the wrong
collation. We don't want planning to fail in cases where the query itself
would work, so this means that we *must* use the query's collation when
invoking operators for estimation purposes.
The only real problem this creates is in ineq_histogram_selectivity, where
the binary search might produce a garbage answer if we perform comparisons
using a different collation than the column's histogram is ordered with.
However, when the query's collation is significantly different from the
column's default collation, the estimate we previously generated would be
pretty irrelevant anyway; so it's not clear that this will result in
noticeably worse estimates in practice. (A follow-on patch will improve
this situation in HEAD, but it seems too invasive for back-patch.)
The patch requires changing the signatures of mcv_selectivity and allied
functions, which are exported and very possibly are used by extensions.
In HEAD, I just did that, but an API/ABI break of this sort isn't
acceptable in stable branches. Therefore, in v12 the patch introduces
"mcv_selectivity_ext" and so on, with signatures matching HEAD, and makes
the old functions into wrappers that assume DEFAULT_COLLATION_OID should
be used. That does not match the prior behavior, but it should avoid risk
of failure in most cases. (In practice, I think most extension datatypes
aren't collation-aware, so the change probably doesn't matter to them.)
Per report from James Lucas. Back-patch to v12 where the problem was
introduced.
Discussion: https://postgr.es/m/CAAFmbbOvfi=wMM=3qRsPunBSLb8BFREno2oOzSBS=mzfLPKABw@mail.gmail.com
Includes some manual cleanup of places that pgindent messed up,
most of which weren't per project style anyway.
Notably, it seems some people didn't absorb the style rules of
commit c9d297751, because there were a bunch of new occurrences
of function calls with a newline just after the left paren, all
with faulty expectations about how the rest of the call would get
indented.
Fix lquery parsing to handle repeated flag characters correctly,
and to enforce the max label length correctly in some cases where
it did not before, and to detect empty labels in some cases where
it did not before.
In a more cosmetic vein, use a switch rather than if-then chains to
handle the different states, and avoid unnecessary checks on charlen
when looking for ASCII characters, and factor out multiple copies of
the label length checking code.
Tom Lane and Dmitry Belyavsky
Discussion: https://postgr.es/m/CADqLbzLVkBuPX0812o+z=c3i6honszsZZ6VQOSKR3VPbB56P3w@mail.gmail.com
Not much to say here --- does what it says on the tin. The "binary"
representation in each case is really just the same as the text format,
though we prefix a version-number byte in case anyone ever feels
motivated to change that. Thus, there's not any expectation of improved
speed or reduced space; the point here is just to allow clients to use
binary format for all columns of a query result or COPY data.
This makes use of the recently added ALTER TYPE support to add binary
I/O functions to an existing data type. As in commit a80818605,
we can piggy-back on there already being a new-for-v13 version of the
ltree extension, so we don't need a new update script file.
Nino Floris, reviewed by Alexander Korotkov and myself
Discussion: https://postgr.es/m/CANmj9Vxx50jOo1L7iSRxd142NyTz6Bdcgg7u9P3Z8o0=HGkYyQ@mail.gmail.com
Quite a few matching operators such as JSONB's @> used "contsel" and
"contjoinsel" as their selectivity estimators. That was a bad idea,
because (a) contsel is only a stub, yielding a fixed default estimate,
and (b) that default is 0.001, meaning we estimate these operators as
five times more selective than equality, which is surely pretty silly.
There's a good model for improving this in ltree's ltreeparentsel():
for any "var OP constant" query, we can try applying the operator
to all of the column's MCV and histogram values, taking the latter
as being a random sample of the non-MCV values. That code is
actually 100% generic, except for the question of exactly what
default selectivity ought to be plugged in when we don't have stats.
Hence, migrate the guts of ltreeparentsel() into the core code, provide
wrappers "matchingsel" and "matchingjoinsel" with a more-appropriate
default estimate, and use those for the non-geometric operators that
formerly used contsel (mostly JSONB containment operators and tsquery
matching).
Also apply this code to some match-like operators in hstore, ltree, and
pg_trgm, including the former users of ltreeparentsel as well as ones
that improperly used contsel. Since commit 911e70207 just created new
versions of those extensions that we haven't released yet, we can sneak
this change into those new versions instead of having to create an
additional generation of update scripts.
Patch by me, reviewed by Alexey Bashtanov
Discussion: https://postgr.es/m/12237.1582833074@sss.pgh.pa.us
The existing implementation of the ltree ~ lquery match operator is
sufficiently complex and undocumented that it's hard to tell exactly
what it does. But one thing it clearly gets wrong is the combination
of NOT symbols (!) and '*' symbols. A pattern such as '*.!foo.*'
should, by any ordinary understanding of regular expression behavior,
match any ltree that has at least one label that's not "foo". As best
we can tell by experimentation, what it's actually matching is any
ltree in which *no* label is "foo". That's surprising, and not at all
what the documentation says.
Now, that's arguably a useful behavior, so if we rewrite to fix the
bug we should provide some other way to get it. To do so, add the
ability to attach lquery quantifiers to non-'*' items as well as '*'s.
Then the pattern '!foo{,}' expresses "any ltree in which no label is
foo". For backwards compatibility, the default quantifier for non-'*'
items has to be "{1}", although the default for '*' items is '{,}'.
I wouldn't have done it like that in a green field, but it's not
totally horrible.
Armed with that, rewrite checkCond() from scratch. Treating '*' and
non-'*' items alike makes it simpler, not more complicated, so that
the function actually gets a lot shorter than it was.
Filip Rembiałkowski, Tom Lane, Nikita Glukhov, per a very
ancient bug report from M. Palm
Discussion: https://postgr.es/m/CAP_rww=waX2Oo6q+MbMSiZ9ktdj6eaJj0cQzNu=Ry2cCDij5fw@mail.gmail.com
Peter Eisentraut