howto/using-merge-subtree.html - pub/scm/git/git-htmldocs - Git at Google

 <?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
     "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
 <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
 <head>
 <meta http-equiv="Content-Type" content="application/xhtml+xml; charset=UTF-8" />
 <meta name="generator" content="AsciiDoc 8.6.10" />
 <title>How to use the subtree merge strategy</title>
 <style type="text/css">
 /* Shared CSS for AsciiDoc xhtml11 and html5 backends */

 /* Default font. */
 body {
   font-family: Georgia,serif;
 }

 /* Title font. */
 h1, h2, h3, h4, h5, h6,
 div.title, caption.title,
 thead, p.table.header,
 #toctitle,
 #author, #revnumber, #revdate, #revremark,
 #footer {
   font-family: Arial,Helvetica,sans-serif;
 }

 body {
   margin: 1em 5% 1em 5%;
 }

 a {
   color: blue;
   text-decoration: underline;
 }
 a:visited {
   color: fuchsia;
 }

 em {
   font-style: italic;
   color: navy;
 }

 strong {
   font-weight: bold;
   color: #083194;
 }

 h1, h2, h3, h4, h5, h6 {
   color: #527bbd;
   margin-top: 1.2em;
   margin-bottom: 0.5em;
   line-height: 1.3;
 }

 h1, h2, h3 {
   border-bottom: 2px solid silver;
 }
 h2 {
   padding-top: 0.5em;
 }
 h3 {
   float: left;
 }
 h3 + * {
   clear: left;
 }
 h5 {
   font-size: 1.0em;
 }

 div.sectionbody {
   margin-left: 0;
 }

 hr {
   border: 1px solid silver;
 }

 p {
   margin-top: 0.5em;
   margin-bottom: 0.5em;
 }

 ul, ol, li > p {
   margin-top: 0;
 }
 ul > li     { color: #aaa; }
 ul > li > * { color: black; }

 .monospaced, code, pre {
   font-family: "Courier New", Courier, monospace;
   font-size: inherit;
   color: navy;
   padding: 0;
   margin: 0;
 }
 pre {
   white-space: pre-wrap;
 }

 #author {
   color: #527bbd;
   font-weight: bold;
   font-size: 1.1em;
 }
 #email {
 }
 #revnumber, #revdate, #revremark {
 }

 #footer {
   font-size: small;
   border-top: 2px solid silver;
   padding-top: 0.5em;
   margin-top: 4.0em;
 }
 #footer-text {
   float: left;
   padding-bottom: 0.5em;
 }
 #footer-badges {
   float: right;
   padding-bottom: 0.5em;
 }

 #preamble {
   margin-top: 1.5em;
   margin-bottom: 1.5em;
 }
 div.imageblock, div.exampleblock, div.verseblock,
 div.quoteblock, div.literalblock, div.listingblock, div.sidebarblock,
 div.admonitionblock {
   margin-top: 1.0em;
   margin-bottom: 1.5em;
 }
 div.admonitionblock {
   margin-top: 2.0em;
   margin-bottom: 2.0em;
   margin-right: 10%;
   color: #606060;
 }

 div.content { /* Block element content. */
   padding: 0;
 }

 /* Block element titles. */
 div.title, caption.title {
   color: #527bbd;
   font-weight: bold;
   text-align: left;
   margin-top: 1.0em;
   margin-bottom: 0.5em;
 }
 div.title + * {
   margin-top: 0;
 }

 td div.title:first-child {
   margin-top: 0.0em;
 }
 div.content div.title:first-child {
   margin-top: 0.0em;
 }
 div.content + div.title {
   margin-top: 0.0em;
 }

 div.sidebarblock > div.content {
   background: #ffffee;
   border: 1px solid #dddddd;
   border-left: 4px solid #f0f0f0;
   padding: 0.5em;
 }

 div.listingblock > div.content {
   border: 1px solid #dddddd;
   border-left: 5px solid #f0f0f0;
   background: #f8f8f8;
   padding: 0.5em;
 }

 div.quoteblock, div.verseblock {
   padding-left: 1.0em;
   margin-left: 1.0em;
   margin-right: 10%;
   border-left: 5px solid #f0f0f0;
   color: #888;
 }

 div.quoteblock > div.attribution {
   padding-top: 0.5em;
   text-align: right;
 }

 div.verseblock > pre.content {
   font-family: inherit;
   font-size: inherit;
 }
 div.verseblock > div.attribution {
   padding-top: 0.75em;
   text-align: left;
 }
 /* DEPRECATED: Pre version 8.2.7 verse style literal block. */
 div.verseblock + div.attribution {
   text-align: left;
 }

 div.admonitionblock .icon {
   vertical-align: top;
   font-size: 1.1em;
   font-weight: bold;
   text-decoration: underline;
   color: #527bbd;
   padding-right: 0.5em;
 }
 div.admonitionblock td.content {
   padding-left: 0.5em;
   border-left: 3px solid #dddddd;
 }

 div.exampleblock > div.content {
   border-left: 3px solid #dddddd;
   padding-left: 0.5em;
 }

 div.imageblock div.content { padding-left: 0; }
 span.image img { border-style: none; vertical-align: text-bottom; }
 a.image:visited { color: white; }

 dl {
   margin-top: 0.8em;
   margin-bottom: 0.8em;
 }
 dt {
   margin-top: 0.5em;
   margin-bottom: 0;
   font-style: normal;
   color: navy;
 }
 dd > *:first-child {
   margin-top: 0.1em;
 }

 ul, ol {
     list-style-position: outside;
 }
 ol.arabic {
   list-style-type: decimal;
 }
 ol.loweralpha {
   list-style-type: lower-alpha;
 }
 ol.upperalpha {
   list-style-type: upper-alpha;
 }
 ol.lowerroman {
   list-style-type: lower-roman;
 }
 ol.upperroman {
   list-style-type: upper-roman;
 }

 div.compact ul, div.compact ol,
 div.compact p, div.compact p,
 div.compact div, div.compact div {
   margin-top: 0.1em;
   margin-bottom: 0.1em;
 }

 tfoot {
   font-weight: bold;
 }
 td > div.verse {
   white-space: pre;
 }

 div.hdlist {
   margin-top: 0.8em;
   margin-bottom: 0.8em;
 }
 div.hdlist tr {
   padding-bottom: 15px;
 }
 dt.hdlist1.strong, td.hdlist1.strong {
   font-weight: bold;
 }
 td.hdlist1 {
   vertical-align: top;
   font-style: normal;
   padding-right: 0.8em;
   color: navy;
 }
 td.hdlist2 {
   vertical-align: top;
 }
 div.hdlist.compact tr {
   margin: 0;
   padding-bottom: 0;
 }

 .comment {
   background: yellow;
 }

 .footnote, .footnoteref {
   font-size: 0.8em;
 }

 span.footnote, span.footnoteref {
   vertical-align: super;
 }

 #footnotes {
   margin: 20px 0 20px 0;
   padding: 7px 0 0 0;
 }

 #footnotes div.footnote {
   margin: 0 0 5px 0;
 }

 #footnotes hr {
   border: none;
   border-top: 1px solid silver;
   height: 1px;
   text-align: left;
   margin-left: 0;
   width: 20%;
   min-width: 100px;
 }

 div.colist td {
   padding-right: 0.5em;
   padding-bottom: 0.3em;
   vertical-align: top;
 }
 div.colist td img {
   margin-top: 0.3em;
 }

 @media print {
   #footer-badges { display: none; }
 }

 #toc {
   margin-bottom: 2.5em;
 }

 #toctitle {
   color: #527bbd;
   font-size: 1.1em;
   font-weight: bold;
   margin-top: 1.0em;
   margin-bottom: 0.1em;
 }

 div.toclevel0, div.toclevel1, div.toclevel2, div.toclevel3, div.toclevel4 {
   margin-top: 0;
   margin-bottom: 0;
 }
 div.toclevel2 {
   margin-left: 2em;
   font-size: 0.9em;
 }
 div.toclevel3 {
   margin-left: 4em;
   font-size: 0.9em;
 }
 div.toclevel4 {
   margin-left: 6em;
   font-size: 0.9em;
 }

 span.aqua { color: aqua; }
 span.black { color: black; }
 span.blue { color: blue; }
 span.fuchsia { color: fuchsia; }
 span.gray { color: gray; }
 span.green { color: green; }
 span.lime { color: lime; }
 span.maroon { color: maroon; }
 span.navy { color: navy; }
 span.olive { color: olive; }
 span.purple { color: purple; }
 span.red { color: red; }
 span.silver { color: silver; }
 span.teal { color: teal; }
 span.white { color: white; }
 span.yellow { color: yellow; }

 span.aqua-background { background: aqua; }
 span.black-background { background: black; }
 span.blue-background { background: blue; }
 span.fuchsia-background { background: fuchsia; }
 span.gray-background { background: gray; }
 span.green-background { background: green; }
 span.lime-background { background: lime; }
 span.maroon-background { background: maroon; }
 span.navy-background { background: navy; }
 span.olive-background { background: olive; }
 span.purple-background { background: purple; }
 span.red-background { background: red; }
 span.silver-background { background: silver; }
 span.teal-background { background: teal; }
 span.white-background { background: white; }
 span.yellow-background { background: yellow; }

 span.big { font-size: 2em; }
 span.small { font-size: 0.6em; }

 span.underline { text-decoration: underline; }
 span.overline { text-decoration: overline; }
 span.line-through { text-decoration: line-through; }

 div.unbreakable { page-break-inside: avoid; }


 /*
  * xhtml11 specific
  *
  * */

 div.tableblock {
   margin-top: 1.0em;
   margin-bottom: 1.5em;
 }
 div.tableblock > table {
   border: 3px solid #527bbd;
 }
 thead, p.table.header {
   font-weight: bold;
   color: #527bbd;
 }
 p.table {
   margin-top: 0;
 }
 /* Because the table frame attribute is overriden by CSS in most browsers. */
 div.tableblock > table[frame="void"] {
   border-style: none;
 }
 div.tableblock > table[frame="hsides"] {
   border-left-style: none;
   border-right-style: none;
 }
 div.tableblock > table[frame="vsides"] {
   border-top-style: none;
   border-bottom-style: none;
 }


 /*
  * html5 specific
  *
  * */

 table.tableblock {
   margin-top: 1.0em;
   margin-bottom: 1.5em;
 }
 thead, p.tableblock.header {
   font-weight: bold;
   color: #527bbd;
 }
 p.tableblock {
   margin-top: 0;
 }
 table.tableblock {
   border-width: 3px;
   border-spacing: 0px;
   border-style: solid;
   border-color: #527bbd;
   border-collapse: collapse;
 }
 th.tableblock, td.tableblock {
   border-width: 1px;
   padding: 4px;
   border-style: solid;
   border-color: #527bbd;
 }

 table.tableblock.frame-topbot {
   border-left-style: hidden;
   border-right-style: hidden;
 }
 table.tableblock.frame-sides {
   border-top-style: hidden;
   border-bottom-style: hidden;
 }
 table.tableblock.frame-none {
   border-style: hidden;
 }

 th.tableblock.halign-left, td.tableblock.halign-left {
   text-align: left;
 }
 th.tableblock.halign-center, td.tableblock.halign-center {
   text-align: center;
 }
 th.tableblock.halign-right, td.tableblock.halign-right {
   text-align: right;
 }

 th.tableblock.valign-top, td.tableblock.valign-top {
   vertical-align: top;
 }
 th.tableblock.valign-middle, td.tableblock.valign-middle {
   vertical-align: middle;
 }
 th.tableblock.valign-bottom, td.tableblock.valign-bottom {
   vertical-align: bottom;
 }


 /*
  * manpage specific
  *
  * */

 body.manpage h1 {
   padding-top: 0.5em;
   padding-bottom: 0.5em;
   border-top: 2px solid silver;
   border-bottom: 2px solid silver;
 }
 body.manpage h2 {
   border-style: none;
 }
 body.manpage div.sectionbody {
   margin-left: 3em;
 }

 @media print {
   body.manpage div#toc { display: none; }
 }


 </style>
 <script type="text/javascript">
 /*<![CDATA[*/
 var asciidoc = {  // Namespace.

 /////////////////////////////////////////////////////////////////////
 // Table Of Contents generator
 /////////////////////////////////////////////////////////////////////

 /* Author: Mihai Bazon, September 2002
  * http://students.infoiasi.ro/~mishoo
  *
  * Table Of Content generator
  * Version: 0.4
  *
  * Feel free to use this script under the terms of the GNU General Public
  * License, as long as you do not remove or alter this notice.
  */

  /* modified by Troy D. Hanson, September 2006. License: GPL */
  /* modified by Stuart Rackham, 2006, 2009. License: GPL */

 // toclevels = 1..4.
 toc: function (toclevels) {

   function getText(el) {
     var text = "";
     for (var i = el.firstChild; i != null; i = i.nextSibling) {
       if (i.nodeType == 3 /* Node.TEXT_NODE */) // IE doesn't speak constants.
         text += i.data;
       else if (i.firstChild != null)
         text += getText(i);
     }
     return text;
   }

   function TocEntry(el, text, toclevel) {
     this.element = el;
     this.text = text;
     this.toclevel = toclevel;
   }

   function tocEntries(el, toclevels) {
     var result = new Array;
     var re = new RegExp('[hH]([1-'+(toclevels+1)+'])');
     // Function that scans the DOM tree for header elements (the DOM2
     // nodeIterator API would be a better technique but not supported by all
     // browsers).
     var iterate = function (el) {
       for (var i = el.firstChild; i != null; i = i.nextSibling) {
         if (i.nodeType == 1 /* Node.ELEMENT_NODE */) {
           var mo = re.exec(i.tagName);
           if (mo && (i.getAttribute("class") || i.getAttribute("className")) != "float") {
             result[result.length] = new TocEntry(i, getText(i), mo[1]-1);
           }
           iterate(i);
         }
       }
     }
     iterate(el);
     return result;
   }

   var toc = document.getElementById("toc");
   if (!toc) {
     return;
   }

   // Delete existing TOC entries in case we're reloading the TOC.
   var tocEntriesToRemove = [];
   var i;
   for (i = 0; i < toc.childNodes.length; i++) {
     var entry = toc.childNodes[i];
     if (entry.nodeName.toLowerCase() == 'div'
      && entry.getAttribute("class")
      && entry.getAttribute("class").match(/^toclevel/))
       tocEntriesToRemove.push(entry);
   }
   for (i = 0; i < tocEntriesToRemove.length; i++) {
     toc.removeChild(tocEntriesToRemove[i]);
   }

   // Rebuild TOC entries.
   var entries = tocEntries(document.getElementById("content"), toclevels);
   for (var i = 0; i < entries.length; ++i) {
     var entry = entries[i];
     if (entry.element.id == "")
       entry.element.id = "_toc_" + i;
     var a = document.createElement("a");
     a.href = "#" + entry.element.id;
     a.appendChild(document.createTextNode(entry.text));
     var div = document.createElement("div");
     div.appendChild(a);
     div.className = "toclevel" + entry.toclevel;
     toc.appendChild(div);
   }
   if (entries.length == 0)
     toc.parentNode.removeChild(toc);
 },


 /////////////////////////////////////////////////////////////////////
 // Footnotes generator
 /////////////////////////////////////////////////////////////////////

 /* Based on footnote generation code from:
  * http://www.brandspankingnew.net/archive/2005/07/format_footnote.html
  */

 footnotes: function () {
   // Delete existing footnote entries in case we're reloading the footnodes.
   var i;
   var noteholder = document.getElementById("footnotes");
   if (!noteholder) {
     return;
   }
   var entriesToRemove = [];
   for (i = 0; i < noteholder.childNodes.length; i++) {
     var entry = noteholder.childNodes[i];
     if (entry.nodeName.toLowerCase() == 'div' && entry.getAttribute("class") == "footnote")
       entriesToRemove.push(entry);
   }
   for (i = 0; i < entriesToRemove.length; i++) {
     noteholder.removeChild(entriesToRemove[i]);
   }

   // Rebuild footnote entries.
   var cont = document.getElementById("content");
   var spans = cont.getElementsByTagName("span");
   var refs = {};
   var n = 0;
   for (i=0; i<spans.length; i++) {
     if (spans[i].className == "footnote") {
       n++;
       var note = spans[i].getAttribute("data-note");
       if (!note) {
         // Use [\s\S] in place of . so multi-line matches work.
         // Because JavaScript has no s (dotall) regex flag.
         note = spans[i].innerHTML.match(/\s*\[([\s\S]*)]\s*/)[1];
         spans[i].innerHTML =
           "[<a id='_footnoteref_" + n + "' href='#_footnote_" + n +
           "' title='View footnote' class='footnote'>" + n + "</a>]";
         spans[i].setAttribute("data-note", note);
       }
       noteholder.innerHTML +=
         "<div class='footnote' id='_footnote_" + n + "'>" +
         "<a href='#_footnoteref_" + n + "' title='Return to text'>" +
         n + "</a>. " + note + "</div>";
       var id =spans[i].getAttribute("id");
       if (id != null) refs["#"+id] = n;
     }
   }
   if (n == 0)
     noteholder.parentNode.removeChild(noteholder);
   else {
     // Process footnoterefs.
     for (i=0; i<spans.length; i++) {
       if (spans[i].className == "footnoteref") {
         var href = spans[i].getElementsByTagName("a")[0].getAttribute("href");
         href = href.match(/#.*/)[0];  // Because IE return full URL.
         n = refs[href];
         spans[i].innerHTML =
           "[<a href='#_footnote_" + n +
           "' title='View footnote' class='footnote'>" + n + "</a>]";
       }
     }
   }
 },

 install: function(toclevels) {
   var timerId;

   function reinstall() {
     asciidoc.footnotes();
     if (toclevels) {
       asciidoc.toc(toclevels);
     }
   }

   function reinstallAndRemoveTimer() {
     clearInterval(timerId);
     reinstall();
   }

   timerId = setInterval(reinstall, 500);
   if (document.addEventListener)
     document.addEventListener("DOMContentLoaded", reinstallAndRemoveTimer, false);
   else
     window.onload = reinstallAndRemoveTimer;
 }

 }
 asciidoc.install();
 /*]]>*/
 </script>
 </head>
 <body class="article">
 <div id="header">
 <h1>How to use the subtree merge strategy</h1>
 </div>
 <div id="content">
 <div id="preamble">
 <div class="sectionbody">
 <div class="paragraph"><p>There are situations where you want to include contents in your project
 from an independently developed project. You can just pull from the
 other project as long as there are no conflicting paths.</p></div>
 <div class="paragraph"><p>The problematic case is when there are conflicting files. Potential
 candidates are Makefiles and other standard filenames. You could merge
 these files but probably you do not want to.  A better solution for this
 problem can be to merge the project as its own subdirectory. This is not
 supported by the <em>recursive</em> merge strategy, so just pulling won&#8217;t work.</p></div>
 <div class="paragraph"><p>What you want is the <em>subtree</em> merge strategy, which helps you in such a
 situation.</p></div>
 <div class="paragraph"><p>In this example, let&#8217;s say you have the repository at <code>/path/to/B</code> (but
 it can be a URL as well, if you want). You want to merge the <em>master</em>
 branch of that repository to the <code>dir-B</code> subdirectory in your current
 branch.</p></div>
 <div class="paragraph"><p>Here is the command sequence you need:</p></div>
 <div class="listingblock">
 <div class="content">
 <pre><code>$ git remote add -f Bproject /path/to/B <b>&lt;1&gt;</b>
 $ git merge -s ours --no-commit --allow-unrelated-histories Bproject/master <b>&lt;2&gt;</b>
 $ git read-tree --prefix=dir-B/ -u Bproject/master <b>&lt;3&gt;</b>
 $ git commit -m "Merge B project as our subdirectory" <b>&lt;4&gt;</b>

 $ git pull -s subtree Bproject master <b>&lt;5&gt;</b></code></pre>
 </div></div>
 <div class="colist arabic"><ol>
 <li>
 <p>
 name the other project "Bproject", and fetch.
 </p>
 </li>
 <li>
 <p>
 prepare for the later step to record the result as a merge.
 </p>
 </li>
 <li>
 <p>
 read "master" branch of Bproject to the subdirectory "dir-B".
 </p>
 </li>
 <li>
 <p>
 record the merge result.
 </p>
 </li>
 <li>
 <p>
 maintain the result with subsequent merges using "subtree"
 </p>
 </li>
 </ol></div>
 <div class="paragraph"><p>The first four commands are used for the initial merge, while the last
 one is to merge updates from <em>B project</em>.</p></div>
 </div>
 </div>
 <div class="sect1">
 <h2 id="_comparing_em_subtree_em_merge_with_submodules">Comparing <em>subtree</em> merge with submodules</h2>
 <div class="sectionbody">
 <div class="ulist"><ul>
 <li>
 <p>
 The benefit of using subtree merge is that it requires less
   administrative burden from the users of your repository. It works with
   older (before Git v1.5.2) clients and you have the code right after
   clone.
 </p>
 </li>
 <li>
 <p>
 However if you use submodules then you can choose not to transfer the
   submodule objects. This may be a problem with the subtree merge.
 </p>
 </li>
 <li>
 <p>
 Also, in case you make changes to the other project, it is easier to
   submit changes if you just use submodules.
 </p>
 </li>
 </ul></div>
 </div>
 </div>
 <div class="sect1">
 <h2 id="_additional_tips">Additional tips</h2>
 <div class="sectionbody">
 <div class="ulist"><ul>
 <li>
 <p>
 If you made changes to the other project in your repository, they may
   want to merge from your project. This is possible using subtree&#8201;&#8212;&#8201;it
   can shift up the paths in your tree and then they can merge only the
   relevant parts of your tree.
 </p>
 </li>
 <li>
 <p>
 Please note that if the other project merges from you, then it will
   connect its history to yours, which can be something they don&#8217;t want
   to.
 </p>
 </li>
 </ul></div>
 </div>
 </div>
 </div>
 <div id="footnotes"><hr /></div>
 <div id="footer">
 <div id="footer-text">
 Last updated
  2019-02-19 15:23:45 PST
 </div>
 </div>
 </body>
 </html>
	<?xml version="1.0" encoding="UTF-8"?>
	<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
	"http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
	<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
	<head>
	<meta http-equiv="Content-Type" content="application/xhtml+xml; charset=UTF-8" />
	<meta name="generator" content="AsciiDoc 8.6.10" />
	<title>How to use the subtree merge strategy</title>
	<style type="text/css">
	/* Shared CSS for AsciiDoc xhtml11 and html5 backends */

	/* Default font. */
	body {
	font-family: Georgia,serif;
	}

	/* Title font. */
	h1, h2, h3, h4, h5, h6,
	div.title, caption.title,
	thead, p.table.header,
	#toctitle,
	#author, #revnumber, #revdate, #revremark,
	#footer {
	font-family: Arial,Helvetica,sans-serif;
	}

	body {
	margin: 1em 5% 1em 5%;
	}

	a {
	color: blue;
	text-decoration: underline;
	}
	a:visited {
	color: fuchsia;
	}

	em {
	font-style: italic;
	color: navy;
	}

	strong {
	font-weight: bold;
	color: #083194;
	}

	h1, h2, h3, h4, h5, h6 {
	color: #527bbd;
	margin-top: 1.2em;
	margin-bottom: 0.5em;
	line-height: 1.3;
	}

	h1, h2, h3 {
	border-bottom: 2px solid silver;
	}
	h2 {
	padding-top: 0.5em;
	}
	h3 {
	float: left;
	}
	h3 + * {
	clear: left;
	}
	h5 {
	font-size: 1.0em;
	}

	div.sectionbody {
	margin-left: 0;
	}

	hr {
	border: 1px solid silver;
	}

	p {
	margin-top: 0.5em;
	margin-bottom: 0.5em;
	}

	ul, ol, li > p {
	margin-top: 0;
	}
	ul > li { color: #aaa; }
	ul > li > * { color: black; }

	.monospaced, code, pre {
	font-family: "Courier New", Courier, monospace;
	font-size: inherit;
	color: navy;
	padding: 0;
	margin: 0;
	}
	pre {
	white-space: pre-wrap;
	}

	#author {
	color: #527bbd;
	font-weight: bold;
	font-size: 1.1em;
	}
	#email {
	}
	#revnumber, #revdate, #revremark {
	}

	#footer {
	font-size: small;
	border-top: 2px solid silver;
	padding-top: 0.5em;
	margin-top: 4.0em;
	}
	#footer-text {
	float: left;
	padding-bottom: 0.5em;
	}
	#footer-badges {
	float: right;
	padding-bottom: 0.5em;
	}

	#preamble {
	margin-top: 1.5em;
	margin-bottom: 1.5em;
	}
	div.imageblock, div.exampleblock, div.verseblock,
	div.quoteblock, div.literalblock, div.listingblock, div.sidebarblock,
	div.admonitionblock {
	margin-top: 1.0em;
	margin-bottom: 1.5em;
	}
	div.admonitionblock {
	margin-top: 2.0em;
	margin-bottom: 2.0em;
	margin-right: 10%;
	color: #606060;
	}

	div.content { /* Block element content. */
	padding: 0;
	}

	/* Block element titles. */
	div.title, caption.title {
	color: #527bbd;
	font-weight: bold;
	text-align: left;
	margin-top: 1.0em;
	margin-bottom: 0.5em;
	}
	div.title + * {
	margin-top: 0;
	}

	td div.title:first-child {
	margin-top: 0.0em;
	}
	div.content div.title:first-child {
	margin-top: 0.0em;
	}
	div.content + div.title {
	margin-top: 0.0em;
	}

	div.sidebarblock > div.content {
	background: #ffffee;
	border: 1px solid #dddddd;
	border-left: 4px solid #f0f0f0;
	padding: 0.5em;
	}

	div.listingblock > div.content {
	border: 1px solid #dddddd;
	border-left: 5px solid #f0f0f0;
	background: #f8f8f8;
	padding: 0.5em;
	}

	div.quoteblock, div.verseblock {
	padding-left: 1.0em;
	margin-left: 1.0em;
	margin-right: 10%;
	border-left: 5px solid #f0f0f0;
	color: #888;
	}

	div.quoteblock > div.attribution {
	padding-top: 0.5em;
	text-align: right;
	}

	div.verseblock > pre.content {
	font-family: inherit;
	font-size: inherit;
	}
	div.verseblock > div.attribution {
	padding-top: 0.75em;
	text-align: left;
	}
	/* DEPRECATED: Pre version 8.2.7 verse style literal block. */
	div.verseblock + div.attribution {
	text-align: left;
	}

	div.admonitionblock .icon {
	vertical-align: top;
	font-size: 1.1em;
	font-weight: bold;
	text-decoration: underline;
	color: #527bbd;
	padding-right: 0.5em;
	}
	div.admonitionblock td.content {
	padding-left: 0.5em;
	border-left: 3px solid #dddddd;
	}

	div.exampleblock > div.content {
	border-left: 3px solid #dddddd;
	padding-left: 0.5em;
	}

	div.imageblock div.content { padding-left: 0; }
	span.image img { border-style: none; vertical-align: text-bottom; }
	a.image:visited { color: white; }

	dl {
	margin-top: 0.8em;
	margin-bottom: 0.8em;
	}
	dt {
	margin-top: 0.5em;
	margin-bottom: 0;
	font-style: normal;
	color: navy;
	}
	dd > *:first-child {
	margin-top: 0.1em;
	}

	ul, ol {
	list-style-position: outside;
	}
	ol.arabic {
	list-style-type: decimal;
	}
	ol.loweralpha {
	list-style-type: lower-alpha;
	}
	ol.upperalpha {
	list-style-type: upper-alpha;
	}
	ol.lowerroman {
	list-style-type: lower-roman;
	}
	ol.upperroman {
	list-style-type: upper-roman;
	}

	div.compact ul, div.compact ol,
	div.compact p, div.compact p,
	div.compact div, div.compact div {
	margin-top: 0.1em;
	margin-bottom: 0.1em;
	}

	tfoot {
	font-weight: bold;
	}
	td > div.verse {
	white-space: pre;
	}

	div.hdlist {
	margin-top: 0.8em;
	margin-bottom: 0.8em;
	}
	div.hdlist tr {
	padding-bottom: 15px;
	}
	dt.hdlist1.strong, td.hdlist1.strong {
	font-weight: bold;
	}
	td.hdlist1 {
	vertical-align: top;
	font-style: normal;
	padding-right: 0.8em;
	color: navy;
	}
	td.hdlist2 {
	vertical-align: top;
	}
	div.hdlist.compact tr {
	margin: 0;
	padding-bottom: 0;
	}

	.comment {
	background: yellow;
	}

	.footnote, .footnoteref {
	font-size: 0.8em;
	}

	span.footnote, span.footnoteref {
	vertical-align: super;
	}

	#footnotes {
	margin: 20px 0 20px 0;
	padding: 7px 0 0 0;
	}

	#footnotes div.footnote {
	margin: 0 0 5px 0;
	}

	#footnotes hr {
	border: none;
	border-top: 1px solid silver;
	height: 1px;
	text-align: left;
	margin-left: 0;
	width: 20%;
	min-width: 100px;
	}

	div.colist td {
	padding-right: 0.5em;
	padding-bottom: 0.3em;
	vertical-align: top;
	}
	div.colist td img {
	margin-top: 0.3em;
	}

	@media print {
	#footer-badges { display: none; }
	}

	#toc {
	margin-bottom: 2.5em;
	}

	#toctitle {
	color: #527bbd;
	font-size: 1.1em;
	font-weight: bold;
	margin-top: 1.0em;
	margin-bottom: 0.1em;
	}

	div.toclevel0, div.toclevel1, div.toclevel2, div.toclevel3, div.toclevel4 {
	margin-top: 0;
	margin-bottom: 0;
	}
	div.toclevel2 {
	margin-left: 2em;
	font-size: 0.9em;
	}
	div.toclevel3 {
	margin-left: 4em;
	font-size: 0.9em;
	}
	div.toclevel4 {
	margin-left: 6em;
	font-size: 0.9em;
	}

	span.aqua { color: aqua; }
	span.black { color: black; }
	span.blue { color: blue; }
	span.fuchsia { color: fuchsia; }
	span.gray { color: gray; }
	span.green { color: green; }
	span.lime { color: lime; }
	span.maroon { color: maroon; }
	span.navy { color: navy; }
	span.olive { color: olive; }
	span.purple { color: purple; }
	span.red { color: red; }
	span.silver { color: silver; }
	span.teal { color: teal; }
	span.white { color: white; }
	span.yellow { color: yellow; }

	span.aqua-background { background: aqua; }
	span.black-background { background: black; }
	span.blue-background { background: blue; }
	span.fuchsia-background { background: fuchsia; }
	span.gray-background { background: gray; }
	span.green-background { background: green; }
	span.lime-background { background: lime; }
	span.maroon-background { background: maroon; }
	span.navy-background { background: navy; }
	span.olive-background { background: olive; }
	span.purple-background { background: purple; }
	span.red-background { background: red; }
	span.silver-background { background: silver; }
	span.teal-background { background: teal; }
	span.white-background { background: white; }
	span.yellow-background { background: yellow; }

	span.big { font-size: 2em; }
	span.small { font-size: 0.6em; }

	span.underline { text-decoration: underline; }
	span.overline { text-decoration: overline; }
	span.line-through { text-decoration: line-through; }

	div.unbreakable { page-break-inside: avoid; }


	/*
	* xhtml11 specific
	*
	* */

	div.tableblock {
	margin-top: 1.0em;
	margin-bottom: 1.5em;
	}
	div.tableblock > table {
	border: 3px solid #527bbd;
	}
	thead, p.table.header {
	font-weight: bold;
	color: #527bbd;
	}
	p.table {
	margin-top: 0;
	}
	/* Because the table frame attribute is overriden by CSS in most browsers. */
	div.tableblock > table[frame="void"] {
	border-style: none;
	}
	div.tableblock > table[frame="hsides"] {
	border-left-style: none;
	border-right-style: none;
	}
	div.tableblock > table[frame="vsides"] {
	border-top-style: none;
	border-bottom-style: none;
	}


	/*
	* html5 specific
	*
	* */

	table.tableblock {
	margin-top: 1.0em;
	margin-bottom: 1.5em;
	}
	thead, p.tableblock.header {
	font-weight: bold;
	color: #527bbd;
	}
	p.tableblock {
	margin-top: 0;
	}
	table.tableblock {
	border-width: 3px;
	border-spacing: 0px;
	border-style: solid;
	border-color: #527bbd;
	border-collapse: collapse;
	}
	th.tableblock, td.tableblock {
	border-width: 1px;
	padding: 4px;
	border-style: solid;
	border-color: #527bbd;
	}

	table.tableblock.frame-topbot {
	border-left-style: hidden;
	border-right-style: hidden;
	}
	table.tableblock.frame-sides {
	border-top-style: hidden;
	border-bottom-style: hidden;
	}
	table.tableblock.frame-none {
	border-style: hidden;
	}

	th.tableblock.halign-left, td.tableblock.halign-left {
	text-align: left;
	}
	th.tableblock.halign-center, td.tableblock.halign-center {
	text-align: center;
	}
	th.tableblock.halign-right, td.tableblock.halign-right {
	text-align: right;
	}

	th.tableblock.valign-top, td.tableblock.valign-top {
	vertical-align: top;
	}
	th.tableblock.valign-middle, td.tableblock.valign-middle {
	vertical-align: middle;
	}
	th.tableblock.valign-bottom, td.tableblock.valign-bottom {
	vertical-align: bottom;
	}


	/*
	* manpage specific
	*
	* */

	body.manpage h1 {
	padding-top: 0.5em;
	padding-bottom: 0.5em;
	border-top: 2px solid silver;
	border-bottom: 2px solid silver;
	}
	body.manpage h2 {
	border-style: none;
	}
	body.manpage div.sectionbody {
	margin-left: 3em;
	}

	@media print {
	body.manpage div#toc { display: none; }
	}


	</style>
	<script type="text/javascript">
	/<![CDATA[/
	var asciidoc = { // Namespace.

	/////////////////////////////////////////////////////////////////////
	// Table Of Contents generator
	/////////////////////////////////////////////////////////////////////

	/* Author: Mihai Bazon, September 2002
	* http://students.infoiasi.ro/~mishoo
	*
	* Table Of Content generator
	* Version: 0.4
	*
	* Feel free to use this script under the terms of the GNU General Public
	* License, as long as you do not remove or alter this notice.
	*/

	/* modified by Troy D. Hanson, September 2006. License: GPL */
	/* modified by Stuart Rackham, 2006, 2009. License: GPL */

	// toclevels = 1..4.
	toc: function (toclevels) {

	function getText(el) {
	var text = "";
	for (var i = el.firstChild; i != null; i = i.nextSibling) {
	if (i.nodeType == 3 /* Node.TEXT_NODE */) // IE doesn't speak constants.
	text += i.data;
	else if (i.firstChild != null)
	text += getText(i);
	}
	return text;
	}

	function TocEntry(el, text, toclevel) {
	this.element = el;
	this.text = text;
	this.toclevel = toclevel;
	}

	function tocEntries(el, toclevels) {
	var result = new Array;
	var re = new RegExp('[hH]([1-'+(toclevels+1)+'])');
	// Function that scans the DOM tree for header elements (the DOM2
	// nodeIterator API would be a better technique but not supported by all
	// browsers).
	var iterate = function (el) {
	for (var i = el.firstChild; i != null; i = i.nextSibling) {
	if (i.nodeType == 1 /* Node.ELEMENT_NODE */) {
	var mo = re.exec(i.tagName);
	if (mo && (i.getAttribute("class") \|\| i.getAttribute("className")) != "float") {
	result[result.length] = new TocEntry(i, getText(i), mo[1]-1);
	}
	iterate(i);
	}
	}
	}
	iterate(el);
	return result;
	}

	var toc = document.getElementById("toc");
	if (!toc) {
	return;
	}

	// Delete existing TOC entries in case we're reloading the TOC.
	var tocEntriesToRemove = [];
	var i;
	for (i = 0; i < toc.childNodes.length; i++) {
	var entry = toc.childNodes[i];
	if (entry.nodeName.toLowerCase() == 'div'
	&& entry.getAttribute("class")
	&& entry.getAttribute("class").match(/^toclevel/))
	tocEntriesToRemove.push(entry);
	}
	for (i = 0; i < tocEntriesToRemove.length; i++) {
	toc.removeChild(tocEntriesToRemove[i]);
	}

	// Rebuild TOC entries.
	var entries = tocEntries(document.getElementById("content"), toclevels);
	for (var i = 0; i < entries.length; ++i) {
	var entry = entries[i];
	if (entry.element.id == "")
	entry.element.id = "_toc_" + i;
	var a = document.createElement("a");
	a.href = "#" + entry.element.id;
	a.appendChild(document.createTextNode(entry.text));
	var div = document.createElement("div");
	div.appendChild(a);
	div.className = "toclevel" + entry.toclevel;
	toc.appendChild(div);
	}
	if (entries.length == 0)
	toc.parentNode.removeChild(toc);
	},


	/////////////////////////////////////////////////////////////////////
	// Footnotes generator
	/////////////////////////////////////////////////////////////////////

	/* Based on footnote generation code from:
	* http://www.brandspankingnew.net/archive/2005/07/format_footnote.html
	*/

	footnotes: function () {
	// Delete existing footnote entries in case we're reloading the footnodes.
	var i;
	var noteholder = document.getElementById("footnotes");
	if (!noteholder) {
	return;
	}
	var entriesToRemove = [];
	for (i = 0; i < noteholder.childNodes.length; i++) {
	var entry = noteholder.childNodes[i];
	if (entry.nodeName.toLowerCase() == 'div' && entry.getAttribute("class") == "footnote")
	entriesToRemove.push(entry);
	}
	for (i = 0; i < entriesToRemove.length; i++) {
	noteholder.removeChild(entriesToRemove[i]);
	}

	// Rebuild footnote entries.
	var cont = document.getElementById("content");
	var spans = cont.getElementsByTagName("span");
	var refs = {};
	var n = 0;
	for (i=0; i<spans.length; i++) {
	if (spans[i].className == "footnote") {
	n++;
	var note = spans[i].getAttribute("data-note");
	if (!note) {
	// Use [\s\S] in place of . so multi-line matches work.
	// Because JavaScript has no s (dotall) regex flag.
	note = spans[i].innerHTML.match(/\s\[([\s\S])]\s*/)[1];
	spans[i].innerHTML =
	"[<a id='_footnoteref_" + n + "' href='#_footnote_" + n +
	"' title='View footnote' class='footnote'>" + n + "</a>]";
	spans[i].setAttribute("data-note", note);
	}
	noteholder.innerHTML +=
	"<div class='footnote' id='_footnote_" + n + "'>" +
	"<a href='#_footnoteref_" + n + "' title='Return to text'>" +
	n + "</a>. " + note + "</div>";
	var id =spans[i].getAttribute("id");
	if (id != null) refs["#"+id] = n;
	}
	}
	if (n == 0)
	noteholder.parentNode.removeChild(noteholder);
	else {
	// Process footnoterefs.
	for (i=0; i<spans.length; i++) {
	if (spans[i].className == "footnoteref") {
	var href = spans[i].getElementsByTagName("a")[0].getAttribute("href");
	href = href.match(/#.*/)[0]; // Because IE return full URL.
	n = refs[href];
	spans[i].innerHTML =
	"[<a href='#_footnote_" + n +
	"' title='View footnote' class='footnote'>" + n + "</a>]";
	}
	}
	}
	},

	install: function(toclevels) {
	var timerId;

	function reinstall() {
	asciidoc.footnotes();
	if (toclevels) {
	asciidoc.toc(toclevels);
	}
	}

	function reinstallAndRemoveTimer() {
	clearInterval(timerId);
	reinstall();
	}

	timerId = setInterval(reinstall, 500);
	if (document.addEventListener)
	document.addEventListener("DOMContentLoaded", reinstallAndRemoveTimer, false);
	else
	window.onload = reinstallAndRemoveTimer;
	}

	}
	asciidoc.install();
	/]]>/
	</script>
	</head>
	<body class="article">
	<div id="header">
	<h1>How to use the subtree merge strategy</h1>
	</div>
	<div id="content">
	<div id="preamble">
	<div class="sectionbody">
	<div class="paragraph"><p>There are situations where you want to include contents in your project
	from an independently developed project. You can just pull from the
	other project as long as there are no conflicting paths.</p></div>
	<div class="paragraph"><p>The problematic case is when there are conflicting files. Potential
	candidates are Makefiles and other standard filenames. You could merge
	these files but probably you do not want to. A better solution for this
	problem can be to merge the project as its own subdirectory. This is not
	supported by the <em>recursive</em> merge strategy, so just pulling won’t work.</p></div>
	<div class="paragraph"><p>What you want is the <em>subtree</em> merge strategy, which helps you in such a
	situation.</p></div>
	<div class="paragraph"><p>In this example, let’s say you have the repository at <code>/path/to/B</code> (but
	it can be a URL as well, if you want). You want to merge the <em>master</em>
	branch of that repository to the <code>dir-B</code> subdirectory in your current
	branch.</p></div>
	<div class="paragraph"><p>Here is the command sequence you need:</p></div>
	<div class="listingblock">
	<div class="content">
	<pre><code>$ git remote add -f Bproject /path/to/B <b><1></b>
	$ git merge -s ours --no-commit --allow-unrelated-histories Bproject/master <b><2></b>
	$ git read-tree --prefix=dir-B/ -u Bproject/master <b><3></b>
	$ git commit -m "Merge B project as our subdirectory" <b><4></b>

	$ git pull -s subtree Bproject master <b><5></b></code></pre>
	</div></div>
	<div class="colist arabic"><ol>
	<li>
	<p>
	name the other project "Bproject", and fetch.
	</p>
	</li>
	<li>
	<p>
	prepare for the later step to record the result as a merge.
	</p>
	</li>
	<li>
	<p>
	read "master" branch of Bproject to the subdirectory "dir-B".
	</p>
	</li>
	<li>
	<p>
	record the merge result.
	</p>
	</li>
	<li>
	<p>
	maintain the result with subsequent merges using "subtree"
	</p>
	</li>
	</ol></div>
	<div class="paragraph"><p>The first four commands are used for the initial merge, while the last
	one is to merge updates from <em>B project</em>.</p></div>
	</div>
	</div>
	<div class="sect1">
	<h2 id="_comparing_em_subtree_em_merge_with_submodules">Comparing <em>subtree</em> merge with submodules</h2>
	<div class="sectionbody">
	<div class="ulist"><ul>
	<li>
	<p>
	The benefit of using subtree merge is that it requires less
	administrative burden from the users of your repository. It works with
	older (before Git v1.5.2) clients and you have the code right after
	clone.
	</p>
	</li>
	<li>
	<p>
	However if you use submodules then you can choose not to transfer the
	submodule objects. This may be a problem with the subtree merge.
	</p>
	</li>
	<li>
	<p>
	Also, in case you make changes to the other project, it is easier to
	submit changes if you just use submodules.
	</p>
	</li>
	</ul></div>
	</div>
	</div>
	<div class="sect1">
	<h2 id="_additional_tips">Additional tips</h2>
	<div class="sectionbody">
	<div class="ulist"><ul>
	<li>
	<p>
	If you made changes to the other project in your repository, they may
	want to merge from your project. This is possible using subtree — it
	can shift up the paths in your tree and then they can merge only the
	relevant parts of your tree.
	</p>
	</li>
	<li>
	<p>
	Please note that if the other project merges from you, then it will
	connect its history to yours, which can be something they don’t want
	to.
	</p>
	</li>
	</ul></div>
	</div>
	</div>
	</div>
	<div id="footnotes"><hr /></div>
	<div id="footer">
	<div id="footer-text">
	Last updated
	2019-02-19 15:23:45 PST
	</div>
	</div>
	</body>
	</html>