Re: write() _will_ fail on Mac OS X/XNU if nbytes > INT_MAX

Filipe Cabecinhas [off-list ref] writes:

Sorry for the delay. I've updated the patch to work as you suggested (I think).
It's attached.

A few comments.

First, the formalities.  Please see Documentation/SubmittingPatches,
notably:

   - Please do not send a patch as an attachment.

   - The attached patch does not seem to have any proposed commit
     log message. For this particular change, I expect it would not
     be more than a paragraph of several lines. Please have one.

   - Please sign-off your patch.

Look at patches from other high-value contributors to learn the
style and the tone of log message.  For instance,

    http://article.gmane.org/gmane.comp.version-control.git/223406

is a good example (taken at random).

	/*
         * We format our multi-line comments like this.
         *
         * Nothing other than slash-asterisk/asterisk-slash
         * on the first and the last line of the comment block.
         */

+ssize_t clipped_write(int fildes, const void *buf, size_t nbyte) {
+  if (nbyte > INT_MAX)
+    return write(fildes, buf, INT_MAX);
+  else
+    return write(fildes, buf, nbyte);
+}

Style:

 - opening and closing parentheses of the function body sit on
   lines on their own.

 - one level of indent is 8 places, using a tab.

Perhaps it would look more like this (my MUA may clobber the tabs,
though, before it gets to you):

	ssize_t clipped_write(int fildes, const void *buf, size_t nbyte)
	{
		if (nbyte > INT_MAX)
			nbyte = INT_MAX;
		return write(fildes, buf, nbyte);
	}

I do not want to see this ffile called "write.c"; we will encounter
a platform whose write(2) behaves a way that we do not expect but is
different from this "clipped to INT_MAX" in the future.  The way we
will deal with such a platform is to add a workaround similar to
this patch somewhere in the compat/ directory, but if you squat on
"compat/write.c", it would be a problem for that platform, as it
cannot call its version "compat/write.c".

Perhaps call it "compat/clipped-write.c" or something.

By the way, does your underlying write(2) correctly write INT_MAX
bytes, or did you mean to clip at (INT_MAX-1)? Just double-checking.

Other than that, the patch looks sensible to me.

Thanks.