3779ac62d7
We previously took a hard-line attitude that callers should never print
a null string pointer, and doing so is worthy of an assertion failure
or crash. However, we've long since flushed out any easy-to-find bugs
of that nature. What remains is a lot of code that perhaps could fail
that way in hard-to-reach corner cases. For example, in something as
simple as
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("constraint \"%s\" for table \"%s\" does not exist",
conname, get_rel_name(relid))));
one must wonder whether it's completely guaranteed that get_rel_name
cannot return NULL in this context. If such a situation did occur,
the existing policy converts what might be a pretty minor bug into
a server crash condition. This is not good for robustness.
Hence, let's follow the lead of glibc and print "(null)" instead
of failing. We should, of course, still consider it a bug if that
behavior is reachable in ordinary use; but crashing seems less
desirable than not crashing.
This fix works across-the-board in v12 and up, where we always use
src/port/snprintf.c. Before that, on most platforms we're at the mercy
of the local libc, but it appears that Solaris 10 is the only supported
platform where we'd still get a crash. Most other platforms such as
*BSD, macOS, and Solaris 11 have adopted glibc's behavior at some
point. (AIX and HPUX just print "" not "(null)", but that's close
enough.) I've not checked what Windows' native printf would do, but
it doesn't matter because we've long used snprintf.c on that platform.
In v12 and up, also const-ify related code so that we're not casting
away const on the constant string. This is just neatnik-ism, since
next to no compilers will warn about that.
Discussion: https://postgr.es/m/17098-b960f3616c861f83@postgresql.org
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| contrib | ||
| doc | ||
| src | ||
| .dir-locals.el | ||
| .editorconfig | ||
| .git-blame-ignore-revs | ||
| .gitattributes | ||
| .gitignore | ||
| COPYRIGHT | ||
| GNUmakefile.in | ||
| HISTORY | ||
| Makefile | ||
| README | ||
| README.git | ||
| aclocal.m4 | ||
| configure | ||
| configure.ac | ||
README
PostgreSQL Database Management System ===================================== This directory contains the source code distribution of the PostgreSQL database management system. PostgreSQL is an advanced object-relational database management system that supports an extended subset of the SQL standard, including transactions, foreign keys, subqueries, triggers, user-defined types and functions. This distribution also contains C language bindings. PostgreSQL has many language interfaces, many of which are listed here: https://www.postgresql.org/download/ See the file INSTALL for instructions on how to build and install PostgreSQL. That file also lists supported operating systems and hardware platforms and contains information regarding any other software packages that are required to build or run the PostgreSQL system. Copyright and license information can be found in the file COPYRIGHT. A comprehensive documentation set is included in this distribution; it can be read as described in the installation instructions. The latest version of this software may be obtained at https://www.postgresql.org/download/. For more information look at our web site located at https://www.postgresql.org/.