memctx: calculate manifest more efficiently
Before this patch, "memctx._manifest" updates all entries in the
(parent) manifest. But this is inefficiency, because almost all files
may be clean in that context.
On the other hand, just updating entries for changed "files" specified
at construction causes unexpected abortion, when there is at least one
newly removed file (see issue4470 for detail).
To calculate manifest more efficiently, this patch replaces
"pman.iteritems()" for the loop by "self._status.modified" to avoid
updating entries for clean or removed files
Examination of removal is also omitted, because removed files aren't
treated in this loop (= "self[f]" returns not None always).
$ hg init a
$ cd a
$ touch empty1
$ hg add empty1
$ hg commit -m 'add empty1'
$ touch empty2
$ hg add empty2
$ hg commit -m 'add empty2'
$ hg up -C 0
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ touch empty3
$ hg add empty3
$ hg commit -m 'add empty3'
created new head
$ hg heads
changeset: 2:a1cb177e0d44
tag: tip
parent: 0:1e1d9c4e5b64
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: add empty3
changeset: 1:097d2b0e17f6
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: add empty2
$ hg merge 1
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
Before changeset 05257fd28591, we didn't notice the
empty file that came from rev 1:
$ hg status
M empty2
$ hg commit -m merge
$ hg manifest --debug tip
b80de5d138758541c5f05265ad144ab9fa86d1db 644 empty1
b80de5d138758541c5f05265ad144ab9fa86d1db 644 empty2
b80de5d138758541c5f05265ad144ab9fa86d1db 644 empty3
$ cd ..