CONTRIBUTORS
author Martin von Zweigbergk <martinvonz@google.com>
Mon, 06 Dec 2021 23:17:43 -0800
changeset 48507 58a3be48ddd2
parent 5514 c29efd272395
permissions -rw-r--r--
simplemerge: stop merging file flags As 384df4db6520 (merge: merge file flags together with file content, 2013-01-09) explains, we shouldn't do a 3-way merge of the symlink. However, since 84614212ae39 (flags: actually merge flags in simplemerge, 2020-05-16), we do that in `simplemerge.simplemerge()`. What's more, the merging of the executable flag there isn't actually necessary; it was made a no-op by the very next commit, i.e. 4234c9af515d (flags: read flag from dirstate/disk for workingcopyctx (issue5743), 2020-05-16). I found the overall flag-merging code (not the bit in `simplemerge.py`) very hard to follow, but I think I now finally understand how it works. `mergestate.resolve()` calculates the merged file flags and sets them on the local side of the merge (confusingly by calling `_restore_backup()`). Then it calls `filemerge.filemerge()`, which in turn calls `simplemerge.simplemerge()` (if premerge is enabled). That means that the flags on the local side `fcs.flags()` are already correct when the flag-merging code in `simplemerge.simplemerge()` runs. Interestingly, that code still works when the local side already has the merged value, it just doesn't change the value. Here's a truth table to explain why: ``` BLOMCAR 0000000 0011111 0101011 0111111 1000000 1010000 1100000 1111101 ``` B: Base L: Local O: Other M: Merged flags from `mergestate.resolve()`, i.e. what's called "local" when we get to `simplemerge.simplemerge()` C: `commonflags` in `simplemerge.simplemerge()`, i.e. `M & O` A: `addedflags` in `simplemerge.simplemerge()`, i.e. `(M ^ O) - B` R: Re-merged flags `simplemerge.simplemerge()`, i.e. `C | A` As you can see, the re-merged flags are always unchanged compared to the initial merged flags (R equals M). Therefore, this patch effectively backs out 84614212ae39. (I might later refactor this code to have the flags explicitly passed in.) `simplemerge.simplemerge()` is also called from `contrib/simplemerge.py`, but that code never passes any flags. Differential Revision: https://phab.mercurial-scm.org/D11879

[This file is here for historical purposes, all recent contributors
should appear in the changelog directly]

Andrea Arcangeli <andrea at suse.de>
Thomas Arendsen Hein <thomas at intevation.de>
Goffredo Baroncelli <kreijack at libero.it>
Muli Ben-Yehuda <mulix at mulix.org>
Mikael Berthe <mikael at lilotux.net>
Benoit Boissinot <bboissin at gmail.com>
Brendan Cully <brendan at kublai.com>
Vincent Danjean <vdanjean.ml at free.fr>
Jake Edge <jake at edge2.net>
Michael Fetterman <michael.fetterman at intel.com>
Edouard Gomez <ed.gomez at free.fr>
Eric Hopper <hopper at omnifarious.org>
Alecs King <alecsk at gmail.com>
Volker Kleinfeld <Volker.Kleinfeld at gmx.de>
Vadim Lebedev <vadim at mbdsys.com>
Christopher Li <hg at chrisli.org>
Chris Mason <mason at suse.com>
Colin McMillen <mcmillen at cs.cmu.edu>
Wojciech Milkowski <wmilkowski at interia.pl>
Chad Netzer <chad.netzer at gmail.com>
Bryan O'Sullivan <bos at serpentine.com>
Vicent SeguĂ­ Pascual <vseguip at gmail.com>
Sean Perry <shaleh at speakeasy.net>
Nguyen Anh Quynh <aquynh at gmail.com>
Ollivier Robert <roberto at keltia.freenix.fr>
Alexander Schremmer <alex at alexanderweb.de>
Arun Sharma <arun at sharma-home.net>
Josef "Jeff" Sipek <jeffpc at optonline.net>
Kevin Smith <yarcs at qualitycode.com>
TK Soh <teekaysoh at yahoo.com>
Radoslaw Szkodzinski <astralstorm at gorzow.mm.pl>
Samuel Tardieu <sam at rfc1149.net>
K Thananchayan <thananck at yahoo.com>
Andrew Thompson <andrewkt at aktzero.com>
Michael S. Tsirkin <mst at mellanox.co.il>
Rafael Villar Burke <pachi at mmn-arquitectos.com>
Tristan Wibberley <tristan at wibberley.org>
Mark Williamson <mark.williamson at cl.cam.ac.uk>