Re: [PATCH] Really *do* nothing in while loop

[Michael Tokarev]

jdow wrote:
> From: "James Purser" <purserj@xxxxxxxxxxxxxxxxx>
  while (deflate(&stream, 0) == Z_OK)
-  /* nothing */
+  /* nothing */;
 stream.next_in = buf;
> You guys REALLY do not see the changed semantics here? You are
> changing:
>   while (deflate(&stream, 0) == Z_OK)
>       stream.next_in = buf;
>
> into
>
>   while (deflate(&stream, 0) == Z_OK)
>     ;
>   /* Then the data itself.. */
>   stream.next_in = buf;
>
> I suspect the results of that tiny bit of code would be slightly
> different, especially if "stream.next_in" is volatile, "buf"
> is volatile, or if the assignment to next_in has an effect on
> the "deflate" operation.

As I already said, deflate() in this case does only ONE iteration.
stream.avail_in is NOT changed in the loop (except of the deflate()
itself, where it will be set to 0 - provided out buffer have enouth
room).  So the whole while loop does only ONE iteration, returning
Z_NEED_DATA or something the next one.  So no, the semantics here
(actual semantics) does NOT change.

/mjt
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