remotefilelog: use the correct redirection in tests The test were using '2>%1' which just redirect stderr in the "%1" file. The intend was '2>&1' which redirect stderr on stdin. This impact tests because some commit were picking up this '%1' files. Differential Revision: https://phab.mercurial-scm.org/D7588

remotefilelog: remove most sleep in tests Now that we removed most of the races, we can remove the infamous sleeps. Differential Revision: https://phab.mercurial-scm.org/D7587

remotefilelog: have command wait for background task in the tests We leverage the feature introduced in the two previous commit to have the main command wait for the background task to be finished before returning. All test still pass and instability seems to have gone away. Most of the sleep and explicit wait are now useless and will be cleaned up in later changesets. Differential Revision: https://phab.mercurial-scm.org/D7586

remotefilelog: add a developer option to wait for background processes In order to block the main command on the subprocess exiting, we ensure the repo's ui object will call the subprocess.wait() method to ensure the top-level hg process doesn't exit until all background processes have also done so. Currently, in the tests, most operation spawning background process as followed by commands waiting for these operations to complete. However this waiting is racy. First because it seems like we can start waiting before the background operation actually start, in which case it is prematurely detected as "done". Second, because some commands may spawn multiple background operation for the same operation (eg: rebase can apparently trigger multiple prefetch). The current approach could be updated to maybe handle the first issue, but the second one will never be properly handled. In most case, we do not care that the bg process keep running after the command end. (Since we explicitly wait for them to end before doing anything else). So we add an option to wait on the background process before exiting the command. We'll put it in use in the next changeset. Differential Revision: https://phab.mercurial-scm.org/D7585

procutil: add a option to not fully detach background process When writing test, it is useful to make code pretending to spawn a fully detached process while still actually waiting for it to finish. We add the option to `procutil.runbgcommand`, to do so. We will use this in remote-filelog tests. Differential Revision: https://phab.mercurial-scm.org/D7584

cext-revlog: fixed __delitem__ for uninitialized nodetree This is a bug in a code path that's seldom used, because in practice (at least in the whole test suite), calls to `del index[i:j]` currently just don't happen before the nodetree has been initialized. However, in our current work to replace the nodetree by a Rust implementation, this is of course systematic. In `index_slice_del()`, if the slice start is smaller than `self->length`, the whole of `self->added` has to be cleared. Before this change, the clearing was done only by the call to `index_invalidate_added(self, 0)`, that happens only for initialized nodetrees. Hence the removal was effective only from `start` to `self->length`. The consequence is index corruption, with bogus results in subsequent calls, and in particular errors such as `ValueError("parent out of range")`, due to the fact that parents of entries in `self->added` are now just invalid. This is detected by the rebase tests, under conditions that the nodetree of revlog.c is never initialized. The provided specific test is more direct. Differential Revision: https://phab.mercurial-scm.org/D7603