[webkit-dev] malloc(0)

[Darin Adler]

On Jun 12, 2012, at 3:03 PM, Myles C. Maxfield <myles.maxfield at gmail.com> wrote:

> I noticed that this caused a problem in one particular place (WTF::StringImpl::getData16SlowCase()) where the code allocates (constant * length) bytes for an (empty) string, and provides an accessor that exposes this pointer. This pointer was being passed to ICU, which didn't perform the requested function because it looked like one of the arguments was invalid, even though it was just empty.

I don’t think we should generalize from this one case to a requirement that malloc(0) return a pointer.

In the case you describe, it’s the ICU behavior is what seems strange to me. Almost all other libraries would be happy to take a null pointer and a length to represent a string of zero length. I suggest we put workaround close to the site of that strangeness. I would not object to having that workaround in place even though most platforms won’t run into the problem due to malloc behavior.

I think that Eric’s interest was in greater efficiency by changing our designs to avoid doing malloc(0). I have no strong objection to that either, but it seems worthwhile only if the cost is really significant.

-- Darin