Re: [PATCH] O_CLOEXEC not honored on Windows - handle inheritance chain

Thomas Munro <thomas(dot)munro(at)gmail(dot)com> writes:
> Hearing nothing, pushed.

fairywren is unimpressed:

../pgsql/src/test/modules/test_cloexec/test_cloexec.c: In function 'run_parent_tests':
../pgsql/src/test/modules/test_cloexec/test_cloexec.c:137:29: warning: unused variable 'space_pos' [-Wunused-variable]
137 | char *space_pos;
| ^~~~~~~~~

It's right, but it seems to me that this stanza needs more help than
that:

/*
* Spawn child process with bInheritHandles=TRUE, passing handle values as
* hex strings
*/
snprintf(cmdline, sizeof(cmdline), "\"%s\" %p %p",
GetCommandLine(), h1, h2);

/*
* Find the actual executable path by removing any arguments from
* GetCommandLine().
*/
{
char exe_path[MAX_PATH];
char *space_pos;

GetModuleFileName(NULL, exe_path, sizeof(exe_path));
snprintf(cmdline, sizeof(cmdline), "\"%s\" %p %p",
exe_path, h1, h2);
}

What is the point of that first snprintf(cmdline, ...), when its
result is guaranteed to be overwritten just below?

I'm also dubious about using MAX_PATH here; see the commentary
about MAXPGPATH in pg_config_manual.h. Also, what's the point of
using MAX_PATH when the result is going to be transferred into
cmdline (with a hardwired size of 1024)?

regards, tom lane