ok/jj
1
0
Fork 0
forked from mirrors/jj
Code Pull requests Activity
jj/v0.19.0/technical/conflicts/index.html

1484 lines
No EOL
32 KiB
HTML
Raw Blame History

<!doctype html>
<html lang="en" class="no-js">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width,initial-scale=1">
<link rel="canonical" href="https://martinvonz.github.io/jj/latest/technical/conflicts/">
<link rel="prev" href="../concurrency/">
<link rel="next" href="../../contributing/">
<link rel="icon" href="../../assets/images/favicon.png">
<meta name="generator" content="mkdocs-1.6.0, mkdocs-material-9.5.24">
<title>Conflicts - Jujutsu docs</title>
<link rel="stylesheet" href="../../assets/stylesheets/main.6543a935.min.css">
<link rel="stylesheet" href="../../assets/stylesheets/palette.06af60db.min.css">
<link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
<link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Roboto:300,300i,400,400i,700,700i%7CRoboto+Mono:400,400i,700,700i&display=fallback">
<style>:root{--md-text-font:"Roboto";--md-code-font:"Roboto Mono"}</style>
<script>__md_scope=new URL("../..",location),__md_hash=e=>[...e].reduce((e,_)=>(e<<5)-e+_.charCodeAt(0),0),__md_get=(e,_=localStorage,t=__md_scope)=>JSON.parse(_.getItem(t.pathname+"."+e)),__md_set=(e,_,t=localStorage,a=__md_scope)=>{try{t.setItem(a.pathname+"."+e,JSON.stringify(_))}catch(e){}}</script>
</head>
<body dir="ltr" data-md-color-scheme="default" data-md-color-primary="indigo" data-md-color-accent="indigo">
<input class="md-toggle" data-md-toggle="drawer" type="checkbox" id="__drawer" autocomplete="off">
<input class="md-toggle" data-md-toggle="search" type="checkbox" id="__search" autocomplete="off">
<label class="md-overlay" for="__drawer"></label>
<div data-md-component="skip">
<a href="#first-class-conflicts" class="md-skip">
Skip to content
</a>
</div>
<div data-md-component="announce">
</div>
<div data-md-color-scheme="default" data-md-component="outdated" hidden>
</div>
<header class="md-header md-header--shadow" data-md-component="header">
<nav class="md-header__inner md-grid" aria-label="Header">
<a href="../.." title="Jujutsu docs" class="md-header__button md-logo" aria-label="Jujutsu docs" data-md-component="logo">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M12 8a3 3 0 0 0 3-3 3 3 0 0 0-3-3 3 3 0 0 0-3 3 3 3 0 0 0 3 3m0 3.54C9.64 9.35 6.5 8 3 8v11c3.5 0 6.64 1.35 9 3.54 2.36-2.19 5.5-3.54 9-3.54V8c-3.5 0-6.64 1.35-9 3.54Z"/></svg>
</a>
<label class="md-header__button md-icon" for="__drawer">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M3 6h18v2H3V6m0 5h18v2H3v-2m0 5h18v2H3v-2Z"/></svg>
</label>
<div class="md-header__title" data-md-component="header-title">
<div class="md-header__ellipsis">
<div class="md-header__topic">
<span class="md-ellipsis">
Jujutsu docs
</span>
</div>
<div class="md-header__topic" data-md-component="header-topic">
<span class="md-ellipsis">
Conflicts
</span>
</div>
</div>
</div>
<form class="md-header__option" data-md-component="palette">
<input class="md-option" data-md-color-media="(prefers-color-scheme)" data-md-color-scheme="default" data-md-color-primary="indigo" data-md-color-accent="indigo" aria-label="Switch to system preference" type="radio" name="__palette" id="__palette_0">
<label class="md-header__button md-icon" title="Switch to system preference" for="__palette_1" hidden>
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="m14.3 16-.7-2h-3.2l-.7 2H7.8L11 7h2l3.2 9h-1.9M20 8.69V4h-4.69L12 .69 8.69 4H4v4.69L.69 12 4 15.31V20h4.69L12 23.31 15.31 20H20v-4.69L23.31 12 20 8.69m-9.15 3.96h2.3L12 9l-1.15 3.65Z"/></svg>
</label>
<input class="md-option" data-md-color-media="(prefers-color-scheme: light)" data-md-color-scheme="default" data-md-color-primary="indigo" data-md-color-accent="indigo" aria-label="Switch to light mode" type="radio" name="__palette" id="__palette_1">
<label class="md-header__button md-icon" title="Switch to light mode" for="__palette_2" hidden>
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M12 8a4 4 0 0 0-4 4 4 4 0 0 0 4 4 4 4 0 0 0 4-4 4 4 0 0 0-4-4m0 10a6 6 0 0 1-6-6 6 6 0 0 1 6-6 6 6 0 0 1 6 6 6 6 0 0 1-6 6m8-9.31V4h-4.69L12 .69 8.69 4H4v4.69L.69 12 4 15.31V20h4.69L12 23.31 15.31 20H20v-4.69L23.31 12 20 8.69Z"/></svg>
</label>
<input class="md-option" data-md-color-media="(prefers-color-scheme: dark)" data-md-color-scheme="slate" data-md-color-primary="indigo" data-md-color-accent="indigo" aria-label="Switch to dark mode" type="radio" name="__palette" id="__palette_2">
<label class="md-header__button md-icon" title="Switch to dark mode" for="__palette_0" hidden>
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M12 18c-.89 0-1.74-.2-2.5-.55C11.56 16.5 13 14.42 13 12c0-2.42-1.44-4.5-3.5-5.45C10.26 6.2 11.11 6 12 6a6 6 0 0 1 6 6 6 6 0 0 1-6 6m8-9.31V4h-4.69L12 .69 8.69 4H4v4.69L.69 12 4 15.31V20h4.69L12 23.31 15.31 20H20v-4.69L23.31 12 20 8.69Z"/></svg>
</label>
</form>
<script>var media,input,key,value,palette=__md_get("__palette");if(palette&&palette.color){"(prefers-color-scheme)"===palette.color.media&&(media=matchMedia("(prefers-color-scheme: light)"),input=document.querySelector(media.matches?"[data-md-color-media='(prefers-color-scheme: light)']":"[data-md-color-media='(prefers-color-scheme: dark)']"),palette.color.media=input.getAttribute("data-md-color-media"),palette.color.scheme=input.getAttribute("data-md-color-scheme"),palette.color.primary=input.getAttribute("data-md-color-primary"),palette.color.accent=input.getAttribute("data-md-color-accent"));for([key,value]of Object.entries(palette.color))document.body.setAttribute("data-md-color-"+key,value)}</script>
<label class="md-header__button md-icon" for="__search">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M9.5 3A6.5 6.5 0 0 1 16 9.5c0 1.61-.59 3.09-1.56 4.23l.27.27h.79l5 5-1.5 1.5-5-5v-.79l-.27-.27A6.516 6.516 0 0 1 9.5 16 6.5 6.5 0 0 1 3 9.5 6.5 6.5 0 0 1 9.5 3m0 2C7 5 5 7 5 9.5S7 14 9.5 14 14 12 14 9.5 12 5 9.5 5Z"/></svg>
</label>
<div class="md-search" data-md-component="search" role="dialog">
<label class="md-search__overlay" for="__search"></label>
<div class="md-search__inner" role="search">
<form class="md-search__form" name="search">
<input type="text" class="md-search__input" name="query" aria-label="Search" placeholder="Search" autocapitalize="off" autocorrect="off" autocomplete="off" spellcheck="false" data-md-component="search-query" required>
<label class="md-search__icon md-icon" for="__search">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M9.5 3A6.5 6.5 0 0 1 16 9.5c0 1.61-.59 3.09-1.56 4.23l.27.27h.79l5 5-1.5 1.5-5-5v-.79l-.27-.27A6.516 6.516 0 0 1 9.5 16 6.5 6.5 0 0 1 3 9.5 6.5 6.5 0 0 1 9.5 3m0 2C7 5 5 7 5 9.5S7 14 9.5 14 14 12 14 9.5 12 5 9.5 5Z"/></svg>
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M20 11v2H8l5.5 5.5-1.42 1.42L4.16 12l7.92-7.92L13.5 5.5 8 11h12Z"/></svg>
</label>
<nav class="md-search__options" aria-label="Search">
<button type="reset" class="md-search__icon md-icon" title="Clear" aria-label="Clear" tabindex="-1">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M19 6.41 17.59 5 12 10.59 6.41 5 5 6.41 10.59 12 5 17.59 6.41 19 12 13.41 17.59 19 19 17.59 13.41 12 19 6.41Z"/></svg>
</button>
</nav>
</form>
<div class="md-search__output">
<div class="md-search__scrollwrap" data-md-scrollfix>
<div class="md-search-result" data-md-component="search-result">
<div class="md-search-result__meta">
Initializing search
</div>
<ol class="md-search-result__list" role="presentation"></ol>
</div>
</div>
</div>
</div>
</div>
</nav>
</header>
<div class="md-container" data-md-component="container">
<main class="md-main" data-md-component="main">
<div class="md-main__inner md-grid">
<div class="md-sidebar md-sidebar--primary" data-md-component="sidebar" data-md-type="navigation" >
<div class="md-sidebar__scrollwrap">
<div class="md-sidebar__inner">
<nav class="md-nav md-nav--primary" aria-label="Navigation" data-md-level="0">
<label class="md-nav__title" for="__drawer">
<a href="../.." title="Jujutsu docs" class="md-nav__button md-logo" aria-label="Jujutsu docs" data-md-component="logo">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M12 8a3 3 0 0 0 3-3 3 3 0 0 0-3-3 3 3 0 0 0-3 3 3 3 0 0 0 3 3m0 3.54C9.64 9.35 6.5 8 3 8v11c3.5 0 6.64 1.35 9 3.54 2.36-2.19 5.5-3.54 9-3.54V8c-3.5 0-6.64 1.35-9 3.54Z"/></svg>
</a>
Jujutsu docs
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../.." class="md-nav__link">
<span class="md-ellipsis">
Home
</span>
</a>
</li>
<li class="md-nav__item md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_2" >
<label class="md-nav__link" for="__nav_2" id="__nav_2_label" tabindex="0">
<span class="md-ellipsis">
Getting started
</span>
<span class="md-nav__icon md-icon"></span>
</label>
<nav class="md-nav" data-md-level="1" aria-labelledby="__nav_2_label" aria-expanded="false">
<label class="md-nav__title" for="__nav_2">
<span class="md-nav__icon md-icon"></span>
Getting started
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../../install-and-setup/" class="md-nav__link">
<span class="md-ellipsis">
Installation and Setup
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../tutorial/" class="md-nav__link">
<span class="md-ellipsis">
Tutorial and Birds-Eye View
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../github/" class="md-nav__link">
<span class="md-ellipsis">
Working with GitHub
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../windows/" class="md-nav__link">
<span class="md-ellipsis">
Working on Windows
</span>
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item">
<a href="../../FAQ/" class="md-nav__link">
<span class="md-ellipsis">
FAQ
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../cli-reference/" class="md-nav__link">
<span class="md-ellipsis">
CLI Reference
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../testimonials/" class="md-nav__link">
<span class="md-ellipsis">
Testimonials
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../community_tools/" class="md-nav__link">
<span class="md-ellipsis">
Community-built tools
</span>
</a>
</li>
<li class="md-nav__item md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_7" >
<label class="md-nav__link" for="__nav_7" id="__nav_7_label" tabindex="0">
<span class="md-ellipsis">
Concepts
</span>
<span class="md-nav__icon md-icon"></span>
</label>
<nav class="md-nav" data-md-level="1" aria-labelledby="__nav_7_label" aria-expanded="false">
<label class="md-nav__title" for="__nav_7">
<span class="md-nav__icon md-icon"></span>
Concepts
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../../working-copy/" class="md-nav__link">
<span class="md-ellipsis">
Working Copy
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../branches/" class="md-nav__link">
<span class="md-ellipsis">
Branches
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../conflicts/" class="md-nav__link">
<span class="md-ellipsis">
Conflicts
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../operation-log/" class="md-nav__link">
<span class="md-ellipsis">
Operation Log
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../glossary/" class="md-nav__link">
<span class="md-ellipsis">
Glossary
</span>
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_8" >
<label class="md-nav__link" for="__nav_8" id="__nav_8_label" tabindex="0">
<span class="md-ellipsis">
Configuration
</span>
<span class="md-nav__icon md-icon"></span>
</label>
<nav class="md-nav" data-md-level="1" aria-labelledby="__nav_8_label" aria-expanded="false">
<label class="md-nav__title" for="__nav_8">
<span class="md-nav__icon md-icon"></span>
Configuration
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../../config/" class="md-nav__link">
<span class="md-ellipsis">
Settings
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../filesets/" class="md-nav__link">
<span class="md-ellipsis">
Fileset language
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../revsets/" class="md-nav__link">
<span class="md-ellipsis">
Revset language
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../templates/" class="md-nav__link">
<span class="md-ellipsis">
Templating language
</span>
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_9" >
<label class="md-nav__link" for="__nav_9" id="__nav_9_label" tabindex="0">
<span class="md-ellipsis">
Comparisons
</span>
<span class="md-nav__icon md-icon"></span>
</label>
<nav class="md-nav" data-md-level="1" aria-labelledby="__nav_9_label" aria-expanded="false">
<label class="md-nav__title" for="__nav_9">
<span class="md-nav__icon md-icon"></span>
Comparisons
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../../git-comparison/" class="md-nav__link">
<span class="md-ellipsis">
Git comparison
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../git-compatibility/" class="md-nav__link">
<span class="md-ellipsis">
Git compatibility
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../sapling-comparison/" class="md-nav__link">
<span class="md-ellipsis">
Sapling
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../related-work/" class="md-nav__link">
<span class="md-ellipsis">
Other related work
</span>
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item md-nav__item--active md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_10" checked>
<label class="md-nav__link" for="__nav_10" id="__nav_10_label" tabindex="0">
<span class="md-ellipsis">
Technical details
</span>
<span class="md-nav__icon md-icon"></span>
</label>
<nav class="md-nav" data-md-level="1" aria-labelledby="__nav_10_label" aria-expanded="true">
<label class="md-nav__title" for="__nav_10">
<span class="md-nav__icon md-icon"></span>
Technical details
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../architecture/" class="md-nav__link">
<span class="md-ellipsis">
Architecture
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../concurrency/" class="md-nav__link">
<span class="md-ellipsis">
Concurrency
</span>
</a>
</li>
<li class="md-nav__item md-nav__item--active">
<input class="md-nav__toggle md-toggle" type="checkbox" id="__toc">
<label class="md-nav__link md-nav__link--active" for="__toc">
<span class="md-ellipsis">
Conflicts
</span>
<span class="md-nav__icon md-icon"></span>
</label>
<a href="./" class="md-nav__link md-nav__link--active">
<span class="md-ellipsis">
Conflicts
</span>
</a>
<nav class="md-nav md-nav--secondary" aria-label="Table of contents">
<label class="md-nav__title" for="__toc">
<span class="md-nav__icon md-icon"></span>
Table of contents
</label>
<ul class="md-nav__list" data-md-component="toc" data-md-scrollfix>
<li class="md-nav__item">
<a href="#introduction" class="md-nav__link">
<span class="md-ellipsis">
Introduction
</span>
</a>
</li>
<li class="md-nav__item">
<a href="#data-model" class="md-nav__link">
<span class="md-ellipsis">
Data model
</span>
</a>
</li>
<li class="md-nav__item">
<a href="#conflict-simplification" class="md-nav__link">
<span class="md-ellipsis">
Conflict simplification
</span>
</a>
</li>
</ul>
</nav>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_11" >
<label class="md-nav__link" for="__nav_11" id="__nav_11_label" tabindex="0">
<span class="md-ellipsis">
Contributing
</span>
<span class="md-nav__icon md-icon"></span>
</label>
<nav class="md-nav" data-md-level="1" aria-labelledby="__nav_11_label" aria-expanded="false">
<label class="md-nav__title" for="__nav_11">
<span class="md-nav__icon md-icon"></span>
Contributing
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../../contributing/" class="md-nav__link">
<span class="md-ellipsis">
Guidelines and "How to...?"
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../code-of-conduct/" class="md-nav__link">
<span class="md-ellipsis">
Code of conduct
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../design_docs/" class="md-nav__link">
<span class="md-ellipsis">
Design Docs
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../design_doc_blueprint/" class="md-nav__link">
<span class="md-ellipsis">
Design Doc Blueprint
</span>
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_12" >
<label class="md-nav__link" for="__nav_12" id="__nav_12_label" tabindex="0">
<span class="md-ellipsis">
Design docs
</span>
<span class="md-nav__icon md-icon"></span>
</label>
<nav class="md-nav" data-md-level="1" aria-labelledby="__nav_12_label" aria-expanded="false">
<label class="md-nav__title" for="__nav_12">
<span class="md-nav__icon md-icon"></span>
Design docs
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../../design/git-submodules/" class="md-nav__link">
<span class="md-ellipsis">
git-submodules
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../design/git-submodule-storage/" class="md-nav__link">
<span class="md-ellipsis">
git-submodule-storage
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../design/run/" class="md-nav__link">
<span class="md-ellipsis">
JJ run
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../design/sparse-v2/" class="md-nav__link">
<span class="md-ellipsis">
Sparse Patterns v2
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../design/tracking-branches/" class="md-nav__link">
<span class="md-ellipsis">
Tracking branches
</span>
</a>
</li>
</ul>
</nav>
</li>
</ul>
</nav>
</div>
</div>
</div>
<div class="md-sidebar md-sidebar--secondary" data-md-component="sidebar" data-md-type="toc" >
<div class="md-sidebar__scrollwrap">
<div class="md-sidebar__inner">
<nav class="md-nav md-nav--secondary" aria-label="Table of contents">
<label class="md-nav__title" for="__toc">
<span class="md-nav__icon md-icon"></span>
Table of contents
</label>
<ul class="md-nav__list" data-md-component="toc" data-md-scrollfix>
<li class="md-nav__item">
<a href="#introduction" class="md-nav__link">
<span class="md-ellipsis">
Introduction
</span>
</a>
</li>
<li class="md-nav__item">
<a href="#data-model" class="md-nav__link">
<span class="md-ellipsis">
Data model
</span>
</a>
</li>
<li class="md-nav__item">
<a href="#conflict-simplification" class="md-nav__link">
<span class="md-ellipsis">
Conflict simplification
</span>
</a>
</li>
</ul>
</nav>
</div>
</div>
</div>
<div class="md-content" data-md-component="content">
<article class="md-content__inner md-typeset">
<h1 id="first-class-conflicts">First-class conflicts<a class="headerlink" href="#first-class-conflicts" title="Permanent link">&para;</a></h1>
<h2 id="introduction">Introduction<a class="headerlink" href="#introduction" title="Permanent link">&para;</a></h2>
<p>Conflicts can happen when two changes are applied to some state. This document
is about conflicts between changes to files (not about <a href="../concurrency/">conflicts between
changes to branch targets</a>, for example).</p>
<p>For example, if you merge two branches in a repo, there may be conflicting
changes between the two branches. Most DVCSs require you to resolve those
conflicts before you can finish the merge operation. Jujutsu instead records
the conflicts in the commit and lets you resolve the conflict when you feel like
it.</p>
<h2 id="data-model">Data model<a class="headerlink" href="#data-model" title="Permanent link">&para;</a></h2>
<p>When a merge conflict happens, it is recorded as an ordered list of tree objects
linked from the commit (instead of the usual single tree per commit). There will
always be an odd number of trees linked from the commit. You can think of the
first tree as a start tree, and the subsequent pairs of trees to apply the diff
between onto the start. Examples:</p>
<ul>
<li>If the commit has trees A, B, C, D, and E it means that the contents should be
calculated as A+(C-B)+(E-D).</li>
<li>A three-way merge between A and C with B as base can be represented as a
commit with trees A, B, and C, also known as A+(C-B).</li>
</ul>
<p>The resulting tree contents is calculated on demand. Note that we often don't
need to merge the entire tree. For example, when checking out a commit in the
working copy, we only need to merge parts of the tree that differs from the
tree that was previously checked out in the working copy. As another example,
when listing paths with conflicts, we only need to traverse parts of the tree
that cannot be trivially resolved; if only one side modified <code>lib/</code>, then we
don't need to look for conflicts in that sub-tree.</p>
<p>When merging trees, if we can't resolve a sub-tree conflict trivially by looking
at just the tree id, we recurse into the sub-tree. Similarly, if we can't
resolve a file conflict trivially by looking at just the id, we recursive into
the hunks within the file.</p>
<p>See <a href="../../git-compatibility/#format-mapping-details">here</a> for how conflicts are
stored when using the Git commit backend.</p>
<h2 id="conflict-simplification">Conflict simplification<a class="headerlink" href="#conflict-simplification" title="Permanent link">&para;</a></h2>
<p>Remember that a 3-way merge can be written <code>A+C-B</code>. If one of those states is
itself a conflict, then we simply insert the conflict expression there. Then we
simplify by removing canceling terms. These two steps are implemented in
<code>Merge::flatten()</code> and <code>Merge::simplify()</code> in <a href="https://github.com/martinvonz/jj/blob/main/lib/src/merge.rs"><code>merge.rs</code></a>.</p>
<p>For example, let's say commit B is based on A and is rebased to C, where it
results in conflicts (<code>B+C-A</code>), which the user leaves unresolved. If the commit
is then rebased to D, the result will be <code>(B+C-A)+(D-C)</code> (<code>D-C</code> comes from
changing the base from C to D). That expression can be simplified to <code>B+D-A</code>,
which is a regular 3-way merge between B and D with A as base (no trace of C).
This is what lets the user keep old commits rebased to head without resolving
conflicts and still not get messy recursive conflicts.</p>
<p>As another example, let's go through what happens when you back out a conflicted
commit. Let's say we have the usual <code>B+C-A</code> conflict on top of non-conflict
state C. We then back out that change. Backing out ("reverting" in Git-speak) a
change means applying its reverse diff, so the result is <code>(B+C-A)+(A-(B+C-A))</code>,
which we can simplify to just <code>A</code> (i.e. no conflict).</p>
</article>
</div>
<script>var target=document.getElementById(location.hash.slice(1));target&&target.name&&(target.checked=target.name.startsWith("__tabbed_"))</script>
</div>
</main>
<footer class="md-footer">
<div class="md-footer-meta md-typeset">
<div class="md-footer-meta__inner md-grid">
<div class="md-copyright">
Made with
<a href="https://squidfunk.github.io/mkdocs-material/" target="_blank" rel="noopener">
Material for MkDocs
</a>
</div>
</div>
</div>
</footer>
</div>
<div class="md-dialog" data-md-component="dialog">
<div class="md-dialog__inner md-typeset"></div>
</div>
<script id="__config" type="application/json">{"base": "../..", "features": [], "search": "../../assets/javascripts/workers/search.b8dbb3d2.min.js", "translations": {"clipboard.copied": "Copied to clipboard", "clipboard.copy": "Copy to clipboard", "search.result.more.one": "1 more on this page", "search.result.more.other": "# more on this page", "search.result.none": "No matching documents", "search.result.one": "1 matching document", "search.result.other": "# matching documents", "search.result.placeholder": "Type to start searching", "search.result.term.missing": "Missing", "select.version": "Select version"}, "version": {"alias": true, "provider": "mike"}}</script>
<script src="../../assets/javascripts/bundle.081f42fc.min.js"></script>
</body>
</html>
View git blame Copy permalink