summaryrefslogtreecommitdiff
AgeCommit message (Collapse)Author
2018-08-24Remove test for VA_ARGS, implied by C99.Andres Freund
This simplifies logic / reduces duplication in a few headers. Author: Andres Freund Discussion: https://postgr.es/m/97d4b165-192d-3605-749c-f614a0c4e783@2ndquadrant.com
2018-08-24LLVMJIT: LLVMGetHostCPUFeatures now is upstream, use LLMV version if available.Andres Freund
Noticed thanks to buildfarm animal seawasp. Author: Andres Freund Backpatch: v11-, where LLVM based JIT compliation was introduced.
2018-08-24Suppress uninitialized-variable warning in new SCRAM code.Tom Lane
While we generally don't sweat too much about "may be used uninitialized" warnings from older compilers, I noticed that there's a fair number of buildfarm animals that are producing such a warning *only* for this variable. So it seems worth silencing.
2018-08-24Fix documentation for run-time partition pruningMichael Paquier
Since 5220bb7, not only Append, but also MergeAppend support the operation. Author: Amit Langote Discussion: https://postgr.es/m/59d8eb92-4536-c44e-54e2-305b9b3d8eb7@lab.ntt.co.jp
2018-08-23Introduce minimal C99 usage to verify compiler support.Andres Freund
This just converts a few for loops in postgres.c to declare variables in the loop initializer, and uses designated initializers in smgr.c's definition of smgr callbacks. Author: Andres Freund Discussion: https://postgr.es/m/97d4b165-192d-3605-749c-f614a0c4e783@2ndquadrant.com
2018-08-23Require C99 (and thus MSCV 2013 upwards).Andres Freund
In 86d78ef50e01 I enabled configure to check for C99 support, with the goal of checking which platforms support C99. While there are a few machines without C99 support among our buildfarm animals, de-supporting them for v12 was deemed acceptable. While not tested in aforementioned commit, the biggest increase in minimum compiler version comes from MSVC, which gained C99 support fairly late. The subset in MSVC 2013 is sufficient for our needs, at this point. While that is a significant increase in minimum version, the existing windows binaries are already built with a new enough version. Make configure error out if C99 support could not be detected. For MSVC builds, increase the minimum version to 2013. The increase to MSVC 2013 allows us to get rid of VCBuildProject.pm, as that was only required for MSVC 2005/2008. Author: Andres Freund Discussion: https://postgr.es/m/97d4b165-192d-3605-749c-f614a0c4e783@2ndquadrant.com
2018-08-24Add more tests for VACUUM skips with partitioned tablesMichael Paquier
A VACUUM or ANALYZE command listing directly a partitioned table expands it to its partitions, causing all elements of a tree to be processed with individual ownership checks done. This results in different relation skips depending on the ownership policy of a tree, which may not be consistent for a partition tree. This commit adds more tests to ensure that any future refactoring allows to keep a consistent behavior, or at least that any changes done are easily identified and checked. The current behavior of VACUUM with partitioned tables is present since 10. Author: Nathan Bossart Reviewed-by: Michael Paquier Discussion: https://postgr.es/m/DC186201-B01F-4A66-9EC4-F855A957C1F9@amazon.com
2018-08-23Deduplicate code between slot_getallattrs() and slot_getsomeattrs().Andres Freund
Code in slot_getallattrs() is the same as if slot_getsomeattrs() is called with number of attributes specified in the tuple descriptor. Implement it that way instead of duplicating the code between those two functions. This is part of a patchseries abstracting TupleTableSlots so they can store arbitrary forms of tuples, but is a nice enough cleanup on its own. Author: Ashutosh Bapat Reviewed-By: Andres Freund Discussion: https://postgr.es/m/20180220224318.gw4oe5jadhpmcdnm@alap3.anarazel.de
2018-08-23Fix lexing of standard multi-character operators in edge cases.Andrew Gierth
Commits c6b3c939b (which fixed the precedence of >=, <=, <> operators) and 865f14a2d (which added support for the standard => notation for named arguments) created a class of lexer tokens which look like multi-character operators but which have their own token IDs distinct from Op. However, longest-match rules meant that following any of these tokens with another operator character, as in (1<>-1), would cause them to be incorrectly returned as Op. The error here isn't immediately obvious, because the parser would usually still find the correct operator via the Op token, but there were more subtle problems: 1. If immediately followed by a comment or +-, >= <= <> would be given the old precedence of Op rather than the correct new precedence; 2. If followed by a comment, != would be returned as Op rather than as NOT_EQUAL, causing it not to be found at all; 3. If followed by a comment or +-, the => token for named arguments would be lexed as Op, causing the argument to be mis-parsed as a simple expression, usually causing an error. Fix by explicitly checking for the operators in the {operator} code block in addition to all the existing special cases there. Backpatch to 9.5 where the problem was introduced. Analysis and patch by me; review by Tom Lane. Discussion: https://postgr.es/m/87va851ppl.fsf@news-spur.riddles.org.uk
2018-08-23Reduce an unnecessary O(N^3) loop in lexer.Andrew Gierth
The lexer's handling of operators contained an O(N^3) hazard when dealing with long strings of + or - characters; it seems hard to prevent this case from being O(N^2), but the additional N multiplier was not needed. Backpatch all the way since this has been there since 7.x, and it presents at least a mild hazard in that trying to do Bind, PREPARE or EXPLAIN on a hostile query could take excessive time (without honouring cancels or timeouts) even if the query was never executed.
2018-08-23In libpq, don't look up all the hostnames at once.Tom Lane
Historically, we looked up the target hostname in connectDBStart, so that PQconnectPoll did not need to do DNS name resolution. The patches that added multiple-target-host support to libpq preserved this division of labor; but it's really nonsensical now, because it means that if any one of the target hosts fails to resolve in DNS, the connection fails. That negates the no-single-point-of-failure goal of the feature. Additionally, DNS lookups aren't exactly cheap, but the code did them all even if the first connection attempt succeeds. Hence, rearrange so that PQconnectPoll does the lookups, and only looks up a hostname when it's time to try that host. This does mean that PQconnectPoll could block on a DNS lookup --- but if you wanted to avoid that, you should be using hostaddr, as the documentation has always specified. It seems fairly unlikely that any applications would really care whether the lookup occurs inside PQconnectStart or PQconnectPoll. In addition to calling out that fact explicitly, do some other minor wordsmithing in the docs around the multiple-target-host feature. Since this seems like a bug in the multiple-target-host feature, backpatch to v10 where that was introduced. In the back branches, avoid moving any existing fields of struct pg_conn, just in case any third-party code is looking into that struct. Tom Lane, reviewed by Fabien Coelho Discussion: https://postgr.es/m/4913.1533827102@sss.pgh.pa.us
2018-08-23Copy-editing of pg_verify_checksums help and ref pagePeter Eisentraut
Reformat synopsis, put options into better order, make the desciption line a bit shorter, and put more details into the description.
2018-08-23PL/pgSQL: Extend test casePeter Eisentraut
This test was supposed to check the interaction of INOUT and default parameters in a procedure call, but it only checked the case where the parameter was not supplied. Now it also checks the case where the parameter was supplied. It was already working correctly, so no code changes required.
2018-08-23Return type of txid_status is text, not txid_statusAlvaro Herrera
Thinko in commit 857ee8e39. Discovered-by: Gianni Ciolli
2018-08-22doc: Clarify some wording in PL/pgSQL about transactionsPeter Eisentraut
Some text was still claiming that committing transactions was not possible in PL/pgSQL.
2018-08-22Change PROCEDURE to FUNCTION in CREATE TRIGGER syntaxPeter Eisentraut
Since procedures are now a different thing from functions, change the CREATE TRIGGER and CREATE EVENT TRIGGER syntax to use FUNCTION in the clause that specifies the function. PROCEDURE is still accepted for compatibility. pg_dump and ruleutils.c output is not changed yet, because that would require a change in information_schema.sql and thus a catversion change. Reported-by: Peter Geoghegan <pg@bowt.ie> Reviewed-by: Jonathan S. Katz <jonathan.katz@excoventures.com>
2018-08-22Change PROCEDURE to FUNCTION in CREATE OPERATOR syntaxPeter Eisentraut
Since procedures are now a different thing from functions, change the CREATE OPERATOR syntax to use FUNCTION in the clause that specifies the function. PROCEDURE is still accepted for compatibility. Reported-by: Peter Geoghegan <pg@bowt.ie> Reviewed-by: Jonathan S. Katz <jonathan.katz@excoventures.com>
2018-08-22doc: Update uses of the word "procedure"Peter Eisentraut
Historically, the term procedure was used as a synonym for function in Postgres/PostgreSQL. Now we have procedures as separate objects from functions, so we need to clean up the documentation to not mix those terms. In particular, mentions of "trigger procedures" are changed to "trigger functions", and access method "support procedures" are changed to "support functions". (The latter already used FUNCTION in the SQL syntax anyway.) Also, the terminology in the SPI chapter has been cleaned up. A few tests, examples, and code comments are also adjusted to be consistent with documentation changes, but not everything. Reported-by: Peter Geoghegan <pg@bowt.ie> Reviewed-by: Jonathan S. Katz <jonathan.katz@excoventures.com>
2018-08-22Wrap long line in postgresql.conf.sample.Thomas Munro
Per complaint from Michael Paquier.
2018-08-22Provide plan_cache_mode options in postgresql.conf.sample.Thomas Munro
Author: David Rowley Discussion: https://postgr.es/m/CAKJS1f8YkwojSTSg8YjNYCLCXzx0fR7wBR3Gf%2BrA9_52eoPZKg%40mail.gmail.com
2018-08-22Do not dump identity sequences with excluded parent tableMichael Paquier
This commit prevents a crash of pg_dump caused by the exclusion of a table which has identity columns, as the table would be correctly excluded but not its identity sequence. In order to fix that, identity sequences are excluded if the parent table is defined as such. Knowing about such sequences has no meaning without their parent table anyway. Reported-by: Andy Abelisto Author: David Rowley Reviewed-by: Peter Eisentraut, Michael Paquier Discussion: https://postgr.es/m/153479393218.1316.8472285660264976457@wrigleys.postgresql.org Backpatch-through: 10
2018-08-22Add regression tests for VACUUM and ANALYZE with relation skipsMichael Paquier
When a user does not have ownership on a relation, then specific log messages are generated. This new test suite adds coverage for all the possible log messages generated, which will be useful to check the consistency of any refactoring related to ownership checks for relations vacuumed or analyzed. Author: Michael Paquier Reviewed-by: Nathan Bossart Discussion: https://postgr.es/m/20180812222142.GA6097@paquier.xyz
2018-08-21Fix typoAlvaro Herrera
2018-08-21fix typoAlvaro Herrera
2018-08-21Fix typoAlvaro Herrera
2018-08-21Fix set of NLS translation issuesMichael Paquier
While monitoring the code, a couple of issues related to string translation has showed up: - Some routines for auto-updatable views return an error string, which sometimes missed the shot. A comment regarding string translation is added for each routine to help with future features. - GSSAPI authentication missed two translations. - vacuumdb handles non-translated strings. - GetConfigOptionByNum should translate strings. This part is not back-patched as after a minor upgrade this could be surprising for users. Reported-by: Kyotaro Horiguchi Author: Kyotaro Horiguchi Reviewed-by: Michael Paquier, Tom Lane Discussion: https://postgr.es/m/20180810.152131.31921918.horiguchi.kyotaro@lab.ntt.co.jp Backpatch-through: 9.3
2018-08-21Fix typo in description of enable_parallel_hashMichael Paquier
Author: Kyotaro Horiguchi Discussion: https://postgr.es/m/20180821.115841.93250330.horiguchi.kyotaro@lab.ntt.co.jp
2018-08-21Clarify comment about assignment and reset of temp namespace ID in MyProcMichael Paquier
The new wording comes from Álvaro, which I modified a bit. Reported-by: Andres Freund, Álvaro Herrera Author: Álvaro Herrera, Michael Paquier Discussion: https://postgr.es/m/20180809165047.GK13638@paquier.xyz Backpatch-through: 11
2018-08-19MSVC: Finish clean.bat tmp_check coverage.Noah Misch
Use wildcards, so one can add a TAP test suite without updating this file. Back-patch to v11, which omitted multiple new suites.
2018-08-19MSVC: Remove any tmp_check directory before running a TAP test suite.Noah Misch
Back-patch to v11, where commit 90627cf98a8e7d0531789391fd798c9bfcc3bc1a made the GNU make build system do likewise. Without this, when a typical PostgresNode-using test failed, subsequent runs bailed out with a "File exists" error.
2018-08-18Improve error messages for CREATE OR REPLACE PROCEDUREPeter Eisentraut
Change the hint to recommend DROP PROCEDURE instead of FUNCTION. Also make the error message when changing the return type more specific to the case of procedures. Reported-by: Jeremy Evans <code@jeremyevans.net> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
2018-08-18Doc: remove obsolete advice about manually inserting snprintf into build.Tom Lane
This para is obsolete, first because nobody is using Solaris 7 anymore, and second because if someone was, configure should catch the snprintf buffer overrun problem automatically (since commit 9bed827b1), and third because this is incorrect advice about how to manually force use of snprintf.c anyway, and has been so at least since commit 3bc6bdf32. The lack of complaints about it reinforces the conclusion that Solaris 7 no longer exists in the wild; so I don't feel a need to insert correct advice instead.
2018-08-17Ensure schema qualification in pg_restore DISABLE/ENABLE TRIGGER commands.Tom Lane
Previously, this code blindly followed the common coding pattern of passing PQserverVersion(AH->connection) as the server-version parameter of fmtQualifiedId. That works as long as we have a connection; but in pg_restore with text output, we don't. Instead we got a zero from PQserverVersion, which fmtQualifiedId interpreted as "server is too old to have schemas", and so the name went unqualified. That still accidentally managed to work in many cases, which is probably why this ancient bug went undetected for so long. It only became obvious in the wake of the changes to force dump/restore to execute with restricted search_path. In HEAD/v11, let's deal with this by ripping out fmtQualifiedId's server- version behavioral dependency, and just making it schema-qualify all the time. We no longer support pg_dump from servers old enough to need the ability to omit schema name, let alone restoring to them. (Also, the few callers outside pg_dump already didn't work with pre-schema servers.) In older branches, that's not an acceptable solution, so instead just tweak the DISABLE/ENABLE TRIGGER logic to ensure it will schema-qualify its output regardless of server version. Per bug #15338 from Oleg somebody. Back-patch to all supported branches. Discussion: https://postgr.es/m/153452458706.1316.5328079417086507743@wrigleys.postgresql.org
2018-08-17InsertPgAttributeTuple() to set attcacheoffPeter Eisentraut
InsertPgAttributeTuple() is the interface between in-memory tuple descriptors and on-disk pg_attribute, so it makes sense to give it the job of resetting attcacheoff. This avoids having all the callers having to do so. Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
2018-08-17Set scan direction appropriately for SubPlans (bug #15336)Andrew Gierth
When executing a SubPlan in an expression, the EState's direction field was left alone, resulting in an attempt to execute the subplan backwards if it was encountered during a backwards scan of a cursor. Also, though much less likely, it was possible to reach the execution of an InitPlan while in backwards-scan state. Repair by saving/restoring estate->es_direction and forcing forward scan mode in the relevant places. Backpatch all the way, since this has been broken since 8.3 (prior to commit c7ff7663e, SubPlans had their own EStates rather than sharing the parent plan's, so there was no confusion over scan direction). Per bug #15336 reported by Vladimir Baranoff; analysis and patch by me, review by Tom Lane. Discussion: https://postgr.es/m/153449812167.1304.1741624125628126322@wrigleys.postgresql.org
2018-08-17Fix configure's snprintf test so it exposes HP-UX bug.Tom Lane
Since commit e1d19c902, buildfarm member gharial has been failing with symptoms indicating that snprintf sometimes returns -1 for buffer overrun, even though it passes the added configure check. Some google research suggests that this happens only in limited cases, such as when the overrun happens partway through a %d item. Adjust the configure check to exercise it that way. Since I'm now feeling more paranoid than I was before, also make the test explicitly verify that the buffer doesn't get physically overrun.
2018-08-17pg_upgrade: issue helpful error message for use on standbysBruce Momjian
Commit 777e6ddf1723306bd2bf8fe6f804863f459b0323 checked for a shut down message from a standby and allowed it to continue. This patch reports a helpful error message in these cases, suggesting to use rsync as documented. Diagnosed-by: Martín Marqués Discussion: https://postgr.es/m/CAPdiE1xYCow-reLjrhJ9DqrMu-ppNq0ChUUEvVdxhdjGRD5_eA@mail.gmail.com Backpatch-through: 9.3
2018-08-17Mention ownership requirements for REFRESH MATERIALIZED VIEW in docsMichael Paquier
Author: Dian Fay Discussion: https://postgr.es/m/745abbd2-a1a0-ead8-2cb2-768c16747d97@gmail.com Backpatch-through: 9.3
2018-08-17Proof-reading for documentation.Thomas Munro
Somebody accidentally a word. Back-patch to 9.6. Reported-by: Justin Pryzby Discussion: https://postgr.es/m/20180816195431.GA23707%40telsasoft.com
2018-08-16Remove unused configure test for ldopen()Peter Eisentraut
unused since f2cc453dd7e87e800a62a173dea0353bf106668d
2018-08-16Use the built-in float datatypes to implement geometric typesTomas Vondra
This patch makes the geometric operators and functions use the exported function of the float4/float8 datatypes. The main reason of doing so is to check for underflow and overflow, and to handle NaNs consciously. The float datatypes consider NaNs values to be equal and greater than all non-NaN values. This change considers NaNs equal only for equality operators. The placement operators, contains, overlaps, left/right of etc. continue to return false when NaNs are involved. We don't need to worry about them being considered greater than any-NaN because there aren't any basic comparison operators like less/greater than for the geometric datatypes. The changes may be summarised as: * Check for underflow, overflow and division by zero * Consider NaN values to be equal * Return NULL when the distance is NaN for all closest point operators * Favour not-NaN over NaN where it makes sense The patch also replaces all occurrences of "double" as "float8". They are the same, but were used inconsistently in the same file. Author: Emre Hasegeli Reviewed-by: Kyotaro Horiguchi, Tomas Vondra Discussion: https://www.postgresql.org/message-id/CAE2gYzxF7-5djV6-cEvqQu-fNsnt%3DEqbOURx7ZDg%2BVv6ZMTWbg%40mail.gmail.com
2018-08-16Remove remaining GEODEBUG references from geo_ops.cTomas Vondra
Commit a7dc63d904a6044d299aebdf59ad3199b6a9e99d removed most of the GEODEBUG occurrences, but there were a couple remaining. So remove them too, to get rid of the macro entirely. Author: Emre Hasegeli Discussion: https://www.postgresql.org/message-id/CAE2gYzxF7-5djV6-cEvqQu-fNsnt%3DEqbOURx7ZDg%2BVv6ZMTWbg%40mail.gmail.com
2018-08-16Require a C99-compliant snprintf(), and remove related workarounds.Tom Lane
Since our substitute snprintf now returns a C99-compliant result, there's no need anymore to have complicated code to cope with pre-C99 behavior. We can just make configure substitute snprintf.c if it finds that the system snprintf() is pre-C99. (Note: I do not believe that there are any platforms where this test will trigger that weren't already being rejected due to our other C99-ish feature requirements for snprintf. But let's add the check for paranoia's sake.) Then, simplify the call sites that had logic to cope with the pre-C99 definition. I also dropped some stuff that was being paranoid about the possibility of snprintf overrunning the given buffer. The only reports we've ever heard of that being a problem were for Solaris 7, which is long dead, and we've sure not heard any reports of these assertions triggering in a long time. So let's drop that complexity too. Likewise, drop some code that wasn't trusting snprintf to set errno when it returns -1. That would be not-per-spec, and again there's no real reason to believe it is a live issue, especially not for snprintfs that pass all of configure's feature checks. Discussion: https://postgr.es/m/17245.1534289329@sss.pgh.pa.us
2018-08-16Fix executor prune failure when plan already prunedAlvaro Herrera
In a multi-layer partitioning setup, if at plan time all the sub-partitions are pruned but the intermediate one remains, the executor later throws a spurious error that there's nothing to prune. That is correct, but there's no reason to throw an error. Therefore, don't. Reported-by: Andreas Seltenreich <seltenreich@gmx.de> Author: David Rowley <david.rowley@2ndquadrant.com> Discussion: https://postgr.es/m/87in4h98i0.fsf@ansel.ydns.eu
2018-08-16Close the file descriptor in ApplyLogicalMappingFileTomas Vondra
The function was forgetting to close the file descriptor, resulting in failures like this: ERROR: 53000: exceeded maxAllocatedDescs (492) while trying to open file "pg_logical/mappings/map-4000-4eb-1_60DE1E08-5376b5-537c6b" LOCATION: OpenTransientFile, fd.c:2161 Simply close the file at the end, and backpatch to 9.4 (where logical decoding was introduced). While at it, fix a nearby typo. Discussion: https://www.postgresql.org/message-id/flat/738a590a-2ce5-9394-2bef-7b1caad89b37%402ndquadrant.com
2018-08-16Try to enable C99 in configure, but do not rely on it (yet).Andres Freund
Based on recent discussion it seems possible that we might start to rely on more of C99. A prerequisite for that is enabling support for that on used compilers. Let's see on which buildfarm members autoconf's AC_PROG_CC_C99() is sufficient to do so. There's probably at least one member where the compiler is too old, but that'd probably be OK. If we go for this permanently we'd likely want to clean out / up a few other configure tests. Note this does not touch the msvc build infrastructure, which'd need separate treatment. Discussion: https://postgr.es/m/20180815222401.kxsupl5zie2jgi4x@alap3.anarazel.de
2018-08-16Update comment in header of errcodes.txtMichael Paquier
This file mentions all the files generated from it, but missed that errcodes-list.sgml is no more, while errcodes-table.sgml is. Author: Noriyoshi Shinoda Discussion: https://postgr.es/m/TU4PR8401MB0430855D6B971E49EB55F328EE3E0@TU4PR8401MB0430.NAMPRD84.PROD.OUTLOOK.COM
2018-08-16Improve comment in GetNewObjectId().Thomas Munro
The previous comment gave the impression that skipping OIDs before FirstNormalObjectId was merely an optimization to avoid likely collisions. In fact other parts of the system have been relying on this threshold to detect system-created objects since commit 8e18d04d4da, so adjust the wording. Author: Thomas Munro Reviewed-by: Tom Lane Discussion: https://postgr.es/m/CAEepm%3D33JASACeOayr_W3%3DCSjy2jiPxM-k89axu0akFbHdjnjA%40mail.gmail.com
2018-08-15Update FSM on WAL replay of page all-visible/frozenAlvaro Herrera
We aren't very strict about keeping FSM up to date on WAL replay, because per-page freespace values aren't critical in replicas (can't write to heap in a replica; and if the replica is promoted, the values would be updated by VACUUM anyway). However, VACUUM since 9.6 can skip processing pages marked all-visible or all-frozen, and if such pages are recorded in FSM with wrong values, those values are blindly propagated to FSM's upper layers by VACUUM's FreeSpaceMapVacuum. (This rationale assumes that crashes are not very frequent, because those would cause outdated FSM to occur in the primary.) Even when the FSM is outdated in standby, things are not too bad normally, because, most per-page FSM values will be zero (other than those propagated with the base-backup that created the standby); only once the remaining free space is less than 0.2*BLCKSZ the per-page value is maintained by WAL replay of heap ins/upd/del. However, if wal_log_hints=on causes complete FSM pages to be propagated to a standby via full-page images, many too-optimistic per-page values can end up being registered in the standby. Incorrect per-page values aren't critical in most cases, since an inserter that is given a page that doesn't actually contain the claimed free space will update FSM with the correct value, and retry until it finds a usable page. However, if there are many such updates to do, an inserter can spend a long time doing them before a usable page is found; in a heavily trafficked insert-only table with many concurrent inserters this has been observed to cause several second stalls, causing visible application malfunction. To fix this problem, it seems sufficient to have heap_xlog_visible (replay of setting all-visible and all-frozen VM bits for a heap page) update the FSM value for the page being processed. This fixes the per-page counters together with making the page skippable to vacuum, so when vacuum does FreeSpaceMapVacuum, the values propagated to FSM upper layers are the correct ones, avoiding the problem. While at it, apply the same fix to heap_xlog_clean (replay of tuple removal by HOT pruning and vacuum). This makes any space freed by the cleaning available earlier than the next vacuum in the promoted replica. Backpatch to 9.6, where this problem was diagnosed on an insert-only table with all-frozen pages, which were introduced as a concept in that release. Theoretically it could apply with all-visible pages to older branches, but there's been no report of that and it doesn't backpatch cleanly anyway. Author: Álvaro Herrera <alvherre@alvh.no-ip.org> Discussion: https://postgr.es/m/20180802172857.5skoexsilnjvgruk@alvherre.pgsql
2018-08-15Clean up assorted misuses of snprintf()'s result value.Tom Lane
Fix a small number of places that were testing the result of snprintf() but doing so incorrectly. The right test for buffer overrun, per C99, is "result >= bufsize" not "result > bufsize". Some places were also checking for failure with "result == -1", but the standard only says that a negative value is delivered on failure. (Note that this only makes these places correct if snprintf() delivers C99-compliant results. But at least now these places are consistent with all the other places where we assume that.) Also, make psql_start_test() and isolation_start_test() check for buffer overrun while constructing their shell commands. There seems like a higher risk of overrun, with more severe consequences, here than there is for the individual file paths that are made elsewhere in the same functions, so this seemed like a worthwhile change. Also fix guc.c's do_serialize() to initialize errno = 0 before calling vsnprintf. In principle, this should be unnecessary because vsnprintf should have set errno if it returns a failure indication ... but the other two places this coding pattern is cribbed from don't assume that, so let's be consistent. These errors are all very old, so back-patch as appropriate. I think that only the shell command overrun cases are even theoretically reachable in practice, but there's not much point in erroneous error checks. Discussion: https://postgr.es/m/17245.1534289329@sss.pgh.pa.us