revlog: specify checkambig at writing to avoid file stat ambiguity This allows revlog-style files to be written out with checkambig=True easily. Because avoiding file stat ambiguity is needed only for filecache-ed manifest and changelog, this patch does: - use False for default value of checkambig - focus only on writing changes of index file out This patch also adds optional argument checkambig to _divert/_delay for changelog, to safely accept checkambig specified in revlog layer. But this argument can be fully ignored, because: - changes are written into other than index file, if name != target - changes are never written into index file, otherwise (into pending file by _divert, or into in-memory buffer by _delay) This is a part of ExactCacheValidationPlan. https://www.mercurial-scm.org/wiki/ExactCacheValidationPlan

vfs: use checkambigatclosing in checkambig=True but atomictemp=False case In Mercurial source tree, opening a file in "a"/"a+" mode like below doesn't specify atomictemp=True for vfs, and this avoids file stat ambiguity check by atomictempfile. - writing changes out in revlog layer uses "a+" mode - truncation in repair.strip() uses "a" mode - truncation in transaction._playback() uses "a" mode If steps below occurs at "the same time in sec", all of mtime, ctime and size are same between (1) and (3). 1. append data to revlog-style file (and close transaction) 2. discard appended data by truncation (strip or rollback) 3. append same size but different data to revlog-style file again Therefore, cache validation doesn't work after (3) as expected. This patch uses checkambigatclosing in checkambig=True but atomictemp=False case, to check (and get rid of) file stat ambiguity at closing. This is a part of ExactCacheValidationPlan. https://www.mercurial-scm.org/wiki/ExactCacheValidationPlan

scmutil: add file object wrapper class to check ambiguity at closing In Mercurial source tree, opening a file in "a"/"a+" mode like below doesn't specify atomictemp=True for vfs, and this avoids file stat ambiguity check by atomictempfile. - writing changes out in revlog layer uses "a+" mode - truncation in repair.strip() uses "a" mode - truncation in transaction._playback() uses "a" mode If steps below occurs at "the same time in sec", all of mtime, ctime and size are same between (1) and (3). 1. append data to revlog-style file (and close transaction) 2. discard appended data by truncation (strip or rollback) 3. append same size but different data to revlog-style file again Therefore, cache validation doesn't work after (3) as expected. This patch adds file object wrapper class checkambigatclosing to check (and get rid of) ambiguity at closing. It is used by vfs in subsequent patch. This is a part of ExactCacheValidationPlan. https://www.mercurial-scm.org/wiki/ExactCacheValidationPlan BTW, checkambigatclosing is tested in test-filecache.py, even though it doesn't use filecache itself, because filecache assumes that file stat ambiguity never occurs (and there is no another test-*.py related to filecache).

scmutil: factor out common logic of delayclosedfile to reuse it This is a preparation for the subsequent patch, which adds another proxy class for a file object.

spartan: remove unused templates

monoblue: remove unused templates

gitweb: remove unused templates

paper: remove unused templates

help: add sections for revsets

help: move revsets.## documentation into infix section

help: clarify quotes are needed for filesets.size expressions

paper: remove unused template "changelogchild"

monoblue: remove unused template "changelogchild"

gitweb: remove unused template "changelogchild"

monoblue: tweak branch table's last row's cell colspan on summary page This table only has 3 columns, so max sensible colspan is 3.

gitweb: tweak branch table's last row's cell colspan on summary page This table only has 3 columns, so max sensible colspan is 3.

tests: clarify demandimport disabled state

demandimport: add trailing comma

tests: favor single quotes for wrapping hg help ...

samplehgrcs: use single quotes in use warning

util: use single quotes in use warning

obsolete: use single quotes in use warning

localrepo: use single quotes in use warning

help: use single quotes in use warning

discovery: use single quotes in use warning

serve: use single quotes in use warning

bundle: use single quotes in use warning

histedit: use single quotes in use warning

keyword: use single quotes in use warning

mq: use single quotes in use warning