convert: when getting file from Perforce concatenate data at the end As it turned out, even when getting relatively small files, concatenating string data every time when new chunk is received is very inefficient. Maintaining a string list of data chunks and concatenating everything in one go at the end seems much more efficient - in my testing it made getting 40 MB file 7 times faster, whilst converting of a particularly big changelist with some big files went down from 20 hours to 3 hours.

help: scripting help topic There are a lot of non-human consumers of Mercurial. And the challenges and considerations for machines consuming Mercurial is significantly different from what humans face. I think there are enough special considerations around how machines consume Mercurial that a dedicated help topic is warranted. I concede the audience for this topic is probably small compared to the general audience. However, lots of normal Mercurial users do things like create one-off shell scripts for common workflows that I think this is useful enough to be in the install (as opposed to, say, a wiki page - which most users will likely never find). This text is by no means perfect. But you have to start somewhere. I think I did cover the important parts, though.

convert: document convert.hg.startrev

transplant: restore dirstate correctly at unexpected failure Before this patch, transplant can't restore dirstate as expected at failure other than one while patching. This causes: - unexpected file status - dirstate refers already rollback-ed parent (only at failure of transplanting the 2nd or later revision) To restore dirstate correctly also at unexpected failure, this patch encloses scope of store lock and transaction by 'dirstateguard'. This is temporary fixing for stable branch. See DirstateTransactionPlan wiki page for detail about the future plan to treat dirstate consistently around scope boundary of transaction. https://mercurial.selenic.com/wiki/DirstateTransactionPlan This patch also adds 'if lock' examination for safety 'lock.release()', because creating 'dirstateguard' object may fail unexpectedly (e.g. IOError for saving dirstate). BTW, in the test script, putting section header '[extensions]' into '.hg/hgrc' is needed to fix incomplete disabling 'abort' extension at 4d1382fd96ff.

localrepo: make journal.dirstate contain in-memory changes before transaction Before this patch, in-memory dirstate changes aren't written out at opening transaction, even though 'journal.dirstate' is created directly from '.hg/dirstate'. Therefore, subsequent 'hg rollback' uses incomplete 'undo.dirstate' to restore dirstate, if dirstate is changed and isn't written out before opening transaction. In cases below, the condition "dirstate is changed and isn't written out before opening transaction" isn't satisfied and this problem doesn't appear: - "wlock scope" and "transaction scope" are almost equivalent e.g. 'commit --amend', 'import' and so on - dirstate changes are written out before opening transaction e.g. 'rebase' (via 'dirstateguard') and 'commit -A' (by separated wlock scopes) On the other hand, 'backout' may satisfy the condition above. To make 'journal.dirstate' contain in-memory changes before opening transaction, this patch explicitly invokes 'dirstate.write()' in 'localrepository.transaction()'. 'dirstate.write()' is placed before not "writing journal files out" but "invoking pretxnopen hooks" for visibility of dirstate changes to external hook processes. BTW, in the test script, 'touch -t 200001010000' and 'hg status' are invoked to make file 'c' surely clean in dirstate, because "clean but unsure" files indirectly cause 'dirstate.write()' at 'repo.status()' in 'repo.commit()' (see fe03f522dda9 for detail) and prevents from certainly reproducing the issue.

dirstate: ensure mv source is marked deleted when walking icasefs (issue4760) Previously, importing a case-only rename patch on a case insensitive filesystem caused the original file to be marked as '!' in status. The source was being forgotten properly in patch.workingbackend.close(), but the call it makes to scmutil.marktouched() then put the file back into the 'n' state (but it was still missing from the filesystem). The cause of this was scmutil._interestingfiles() would walk dirstate, and since dirstate was able to lstat() the old file via the new name, was treating this as a forgotten file, not a removed file. scmutil.marktouched() re-adds forgotten files, so dirstate got out of sync with the filesystem. This could be handled with less code in the "kind == regkind or kind == lnkkind" branch of dirstate._walkexplicit(), but this avoids filesystem accesses unless case collisions occur. _discoverpath() is used instead of normalize(), since the dirstate case is given first precedence, and the old file is still in it. What matters is the actual case in the filesystem.

extdiff: allow modifications in subrepos to be copied back This check was a legacy bit from when the file data was being fetched manually with 'ctx[wfn]', but archive() does that now. 49966b5ab16f seems to indicate that this avoided a problem where a merge adds a file to another branch, and that test still passes. Unfortunately, I don't see a way to create a test that modifies the file in the temporary directory before the command exits. I wonder if the os.lstat() call needs to be wrapped in an exception handler for the case where archive didn't create a file because the file didn't exist in that revision. But I wasn't able to trigger a problem without it on a real repository.