Re: [libvirt] [PATCH] error: avoid API breakage with vmware

On 12/21/10 - 03:12:43PM, Eric Blake wrote: > Fix glitch in commit cddd2a06 (thankfully post-0.8.6, so no > released version has the glitch). > > Document and try to workaround glitch in commit 46e9b0f (in 0.8.0, > which invalidated 6 virErrorNumber dating back to 0.7.1). > > Thankfully, my audit did not find any other glitches until pre-0.1.0 > days. I'm not sure how to add a syntax-check off the top of my > head, but hopefully the explicit numbering will make people think > twice about renumbering in the future. > > * include/libvirt/virterror.h (virErrorDomain): Avoid inserting > new values in the middle, and add explicit numbering to help avoid > this in the future. > (virErrorNumber): Add explicit numbering, and document the snafu. > * src/remote/remote_driver.c (remoteIO): Compensate for the snafu. Thanks for looking at this, Eric. > +++ b/src/remote/remote_driver.c > @@ -10371,8 +10371,36 @@ remoteIO(virConnectPtr conn, > return -1; > > cleanup: > - DEBUG("All done with our call %d %p %p", thiscall->proc_nr, priv->waitDispatch, thiscall); > + DEBUG("All done with our call %d %p %p", thiscall->proc_nr, > + priv->waitDispatch, thiscall); > if (thiscall->mode == REMOTE_MODE_ERROR) { > + /* Interop for virErrorNumber glitch in 0.8.0, if server is > + * 0.7.1 through 0.7.7 */

Clever. Make sure it is of the right "domain", and if not, you know you are talking to an older server. At first I thought it was confusing, but this will do the right thing in *almost* all situations, so I like it. ACK to this; as DV says, maybe we can make a "make check" or "make syntax-check" to automatically catch it in the future, but this at least fixes the current breakage.