ec62ce55a8
Previously, a byte with the high bit set was just transmitted as-is by charin() and charout(). This is problematic if the database encoding is multibyte, because the result of charout() won't be validly encoded, which breaks various stuff that expects all text strings to be validly encoded. We've previously decided to enforce encoding validity rather than try to individually harden each place that might have a problem with such strings, so it's time to do something about "char". To fix, represent high-bit-set characters as \ooo (backslash and three octal digits), following the ancient "escape" format for bytea. charin() will continue to accept the old way as well, though that is only reachable in single-byte encodings. Add some test cases just so there is coverage for this code. We'll otherwise leave this question undocumented as it was before, because we don't really want to encourage end-user use of "char". For the moment, back-patch into v15 so that this change appears in 15beta3. If there's not great pushback we should consider absorbing this change into the older branches. Discussion: https://postgr.es/m/2318797.1638558730@sss.pgh.pa.us |
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| .. | ||
| activity | ||
| adt | ||
| cache | ||
| error | ||
| fmgr | ||
| hash | ||
| init | ||
| mb | ||
| misc | ||
| mmgr | ||
| resowner | ||
| sort | ||
| time | ||
| .gitignore | ||
| Gen_dummy_probes.pl | ||
| Gen_dummy_probes.pl.prolog | ||
| Gen_dummy_probes.sed | ||
| Gen_fmgrtab.pl | ||
| Makefile | ||
| README.Gen_dummy_probes | ||
| errcodes.txt | ||
| generate-errcodes.pl | ||
| postprocess_dtrace.sed | ||
| probes.d | ||
README.Gen_dummy_probes
# Generating dummy probes If Postgres isn't configured with dtrace enabled, we need to generate dummy probes for the entries in probes.d, that do nothing. This is accomplished in Unix via the sed script `Gen_dummy_probes.sed`. We used to use this in MSVC builds using the perl utility `psed`, which mimicked sed. However, that utility disappeared from Windows perl distributions and so we converted the sed script to a perl script to be used in MSVC builds. We still keep the sed script as the authoritative source for generating these dummy probes because except on Windows perl is not a hard requirement when building from a tarball. So, if you need to change the way dummy probes are generated, first change the sed script, and when it's working generate the perl script. This can be accomplished by using the perl utility s2p. s2p is no longer part of the perl core, so it might not be on your system, but it is available on CPAN and also in many package systems. e.g. on Fedora it can be installed using `cpan App::s2p` or `dnf install perl-App-s2p`. The Makefile contains a recipe for regenerating Gen_dummy_probes.pl, so all you need to do is once you have s2p installed is `make Gen_dummy_probes.pl` Note that in a VPATH build this will generate the file in the vpath tree, not the source tree.