tests: conditionalize extension tests for extra extensions If extra extensions are loaded (e.g. via --extra-config-opt), the tests conditionalized in this commit fail in ways that are dependent on the extensions that are loaded. So let's skip them when that scenario is present. This drops the number of failures for the simplestorerepo.py extension to 4. Differential Revision: https://phab.mercurial-scm.org/D4285

commit: try hard to reuse p1 manifest if nothing changed This is all for commit reproducibility on "hg convert". With this change, p1 manifest is reused if ctx.files() *to be committed* is empty, and if new manifest entry is identical to p1. This is important property for "hg convert" since memctx.files() built from a convert source may be either a) more narrowed thanks to a committed ctx.files() which provides more accurate status, or b) containing redundant files because of sloppy filtering on e.g. octopus merge.

merge: add tests for commit with no content change It isn't easy to say when to reuse the p1 manifest. Basically, that's only when wctx.files() is empty, but we need to know that wctx.files() is not the same as repo['.'].files() after the commit. This patch adds several examples of commits with empty ctx/wctx.files(). I don't think this is exhaustive, but it contains at least one failure mode in which a converted repo result in a different hash. I also note that the manifest revlog does NOT follow the DAG shape of the changelog since p1 manifest is reused if wctx.files() is empty even at merge. I don't know whether it is intentional or not, but it's the behavior since 2011, 301725c3df9a "localrepo: reuse parent manifest in commitctx if no files have changed."

commit: add debug message regarding manifest reuse

mail: convert encoding.encoding to sysstr

mail: call s.decode('ascii') explicitly to see if s is an ascii bytes

mail: pass in addr to _addressencode() in bytes _addressencode() doesn't process a unicode addr well. For example, acc.encode('ascii') would raise UnicodeEncodeError if acc was a unicode. This patch temporarily restores the pre-952bf3c948f0 _addressencode(). Several tests would be broken on Python 3.