Re: [libvirt] [PATCH v5 0/3] vsh: Introduce new API for printing tables

On Tue, Aug 28, 2018 at 03:52:56PM +0200, Ján Tomko wrote: > On Tue, Aug 28, 2018 at 02:46:08PM +0100, Daniel P. Berrangé wrote: > > On Tue, Aug 28, 2018 at 03:41:26PM +0200, Ján Tomko wrote: > > > On Tue, Aug 28, 2018 at 02:24:19PM +0100, Daniel P. Berrangé wrote: > > > > On Tue, Aug 28, 2018 at 02:24:42PM +0200, Ján Tomko wrote: > > > > > On Tue, Aug 28, 2018 at 02:10:55PM +0200, Erik Skultety wrote: > > > > > > > So how about storing 2 sets of expected data for this test case. > > > > > > > > > > > > > > > > > Two is not enough. My clang 5.0.1 produces a test that displays the > > > > > monkeys correctly, but does not count their width properly: > > > > > > > > Is this a different bug though ? The issue with iswprint() is varying > > > > according to glibc version, not compiler version. > > > > > > > > > > The broken setup is: > > > sys-libs/glibc-2.25-r9 > > > sys-devel/clang-5.0.1 > > > > > > It works on: > > > sys-libs/glibc-2.26-r7 > > > with either of: > > > sys-devel/clang-5.0.1 > > > sys-devel/clang-6.0.1 > > > > > > So yes, it is a glibc bug. > > > Depending on the version, either just wcwidth returns incorrect values > > > for the monkeys (my case) or iswprint considers them non-printable. > > > > It sounds like in your case we're genuinely broken in the virsh > > code, not merely tests broken. > > > > I wonder if we need extra logic in the virsh code to handle escaping > > for the cases where wcwidth is returning wrong data, so we still get > > column layout correct ? > > > > I don't think so. > > 1) wouldn't that involve reimplementing the wcwidth function? > 2) users crazy enough to use new unicode characters are welcome to > upgrade to new glibc, or suffer through misaligned virsh tables. I second that, I don't think that in this case it's any beneficial trying to fix glibc problems just to offer users a consistent experience, we're not gnulib, besides, we're talking about table alignment which has been broken for ages and we've already made a significant progress here. Additionally, as Jano has pointed out, if someone feels adventurous, that's fine, but it may come with certain limitations.