cleanup: remove some unused / duplicate imports

cleanup: fix some list comprehension redefinitions of existing vars In all the remaining cases the comprehension variable is used for the same thing as a previous loop variable. This will mute some pyflakes "list comprehension redefines" warnings.

cleanup: avoid local vars shadowing imports This will mute some pyflakes "import ... shadowed by loop variable" warnings.

cleanup: avoid _ for local unused tmp variables - that is reserved for i18n _ is usually used for i18n markup but we also used it for I-don't-care variables. Instead, name don't-care variables in a slightly descriptive way but use the _ prefix to designate unused variable. This will mute some pyflakes "import '_' ... shadowed by loop variable" warnings.

cleanup: make sure we always access members of imported modules This will make sure we get import errors, even if demandimport is enabled. This will also mute some pyflakes 'imported but unused' warnings.

largefiles: update lfdirstate for unchanged largefiles during linear merging Before this patch, linear merging of modified largefiles causes an unexpected result, if (1) largefile collides with same-name normal one in the target revision and (2) "local" largefile is chosen, even though branch merging between such revisions works correctly. Expected result of such linear merging is marking the largefile as (re-)"added", but the actual result is marking it as "modified". The standin of modified "local largefile" is not changed by linear merging, and updating/merging update lfdirstate entries only for largefiles of which standins are changed. This patch adds the code path to update lfdirstate only for largefiles of which standins are not changed. In this case, "synclfdirstate" should be invoked with True as "normallookup" argument always to force using "normallookup" on dirstate for "n" files, because "normal" may mark target files as "clean" unexpectedly. To reduce cost of "lfile not in filelist", this patch converts "filelist" to a "set" object: "filelist" is used only in (1) the newly added code path and (2) the next line of "filelist = set(filelist)". This is a temporary way to fix with less changes. For fundamental resolution of this kind of problems in the future, "lfdirstate" should be updated with "dirstate" simultaneously during "merge.update" execution: maybe by hooking "recordupdates" (+ total refactoring around lfdirstate handling)

largefiles: keep largefiles from colliding with normal one during linear merge Before this patch, linear merging of modified or newly added largefile causes unexpected result, if (1) largefile collides with same name normal one in the target revision and (2) "local" largefile is chosen, even though branch merging between such revisions doesn't. Expected result of such linear merging is: (1) (not yet recorded) largefile is kept in the working directory (2) largefile is marked as (re-)"added" (3) colliding normal file is marked as "removed" But actual result is: (1) largefile in the working directory is unlinked (2) largefile is marked as "normal" (so treated as "missing") (3) the dirstate entry for colliding normal file is just dropped (1) is very serious, because there is no way to restore temporarily modified largefiles. (3) prevents the next commit from adding the manifest with correct "removal of (normal) file" information for newly created changeset. The root cause of this problem is putting "lfile" into "actions['r']" in linear-merging case. At liner merging, "actions['r']" causes: - unlinking "target file" in the working directory, but "lfile" as "target file" is also largefile itself in this case - dropping the dirstate entry for target file "actions['f']" (= "forget") does only the latter, and this is reason why this patch doesn't choose putting "lfile" into it instead of "actions['r']". This patch newly introduces action "lfmr" (LargeFiles: Mark as Removed) to mark colliding normal file as "removed" without unlinking it. This patch uses "hg debugdirstate" instead of "hg status" in test, because: - choosing "local largefile" hides "removed" status of "remote normal file" in "hg status" output, and - "hg status" for "large2" in this case has another problem fixed in the subsequent patch

largefiles: add test for large/normal conflict at linear merging Before this patch, there is no explicit test for it: test-issue3084.t seems to test such conflict only at branch merging. This patch uses "[debug] dirstate.delaywrite" feature for the tests expecting "M" status of largefiles, to confirm certainly whether files are marked unexpectedly as "clean".

largefiles: put whole "hgmerge" process into the same "wlock" scope Before this patch, there are two distinct "wlock" scopes below in "hgmerge": 1. "merge.update" via original "hg.merge" function 2. "updatelfiles" specific "wlock" scope (to synchronize largefile dirstate) But these should be executed in the same "wlock" scope for consistency, because users of "hg.merge" don't get "wlock" explicitly before invocation of it. - merge in commands This patch puts almost all of the original "hgmerge" implementation into "_hgmerge" to reduce changes.

largefiles: put whole "hgupdaterepo" process into the same "wlock" scope Before this patch, there are two distinct "wlock" scopes below in "hgupdaterepo": 1. "merge.update" via original "hg.updaterepo" function 2. "updatelfiles" specific "wlock" scope (to synchronize largefile dirstate) In addition to them, "dirstate.walk" is executed between these "wlock" scopes. But these should be executed in the same "wlock" scope for consistency, because many (indirect) users of "hg.updaterepo" don't get "wlock" explicitly before invocation of it. "hg.clean" is invoked without "wlock" from: - mqrepo.restore in mq - bisect in commands - update in commands "hg.update" is invoked without "wlock" from: - clone in mq - pullrebase in rebase - postincoming in commands (used in "hg pull -u", "hg unbundle") - update in commands This patch puts almost all original "hgupdaterepo" implementation into "_hgupdaterepo" to reduce changes.

annotate: inline definition of decorate() functions

annotate: rewrite long short-circuit statement by if-elif-else

revert: use modified information from both statuses Using status information against the target ensures we are catching all files with modifications that need reverting. We still need to distinguish fresh modifications for backup purpose. test-largefile is affected because it reverted a file that needs no content change.

revert: drop special case handling for file unknown in parent We had a special case for file not caught by any categories. It was aimed at files missing in wc and wc's parent but existing in the target revision. This is now properly handled using status information.

revert: use "remove" information from both statuses Using status information against the target to make sure we are catching all files that need to be re-added. We still need to distinguish fresh removal because they use a different message.