http://www.eclipse.org/jgit//org.eclipse.jgit: Repository access and algorithms (Eclipse JGit Project)
  • Eclipse Distribution License (New BSD License)
  • Andrey Loskutov
  • Christian Halstrick
  • Dave Borowitz
  • David Pursehouse
  • Gunnar Wagenknecht
  • Jonathan Nieder
  • Jonathan Tan
  • Matthias Sohn
  • Sasa Zivkov
  • Terry Parker
  • Thomas Wolf 
/*
 * Copyright (C) 2010, Christian Halstrick <christian.halstrick@sap.com>,
 * Copyright (C) 2010-2012, Matthias Sohn <matthias.sohn@sap.com>
 * Copyright (C) 2012, Research In Motion Limited
 * Copyright (C) 2017, Obeo (mathieu.cartaud@obeo.fr)
 * Copyright (C) 2018, Thomas Wolf <thomas.wolf@paranor.ch>
 * and other copyright owners as documented in the project's IP log.
 *
 * This program and the accompanying materials are made available
 * under the terms of the Eclipse Distribution License v1.0 which
 * accompanies this distribution, is reproduced below, and is
 * available at http://www.eclipse.org/org/documents/edl-v10.php
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or
 * without modification, are permitted provided that the following
 * conditions are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above
 *   copyright notice, this list of conditions and the following
 *   disclaimer in the documentation and/or other materials provided
 *   with the distribution.
 *
 * - Neither the name of the Eclipse Foundation, Inc. nor the
 *   names of its contributors may be used to endorse or promote
 *   products derived from this software without specific prior
 *   written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.eclipse.jgit.merge;

import static java.nio.charset.StandardCharsets.UTF_8;
import static java.time.Instant.EPOCH;
import static org.eclipse.jgit.diff.DiffAlgorithm.SupportedAlgorithm.HISTOGRAM;
import static org.eclipse.jgit.lib.ConfigConstants.CONFIG_DIFF_SECTION;
import static org.eclipse.jgit.lib.ConfigConstants.CONFIG_KEY_ALGORITHM;
import static org.eclipse.jgit.lib.Constants.OBJ_BLOB;

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.time.Instant;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;

import org.eclipse.jgit.attributes.Attributes;
import org.eclipse.jgit.diff.DiffAlgorithm;
import org.eclipse.jgit.diff.DiffAlgorithm.SupportedAlgorithm;
import org.eclipse.jgit.diff.RawText;
import org.eclipse.jgit.diff.RawTextComparator;
import org.eclipse.jgit.diff.Sequence;
import org.eclipse.jgit.dircache.DirCache;
import org.eclipse.jgit.dircache.DirCacheBuildIterator;
import org.eclipse.jgit.dircache.DirCacheBuilder;
import org.eclipse.jgit.dircache.DirCacheCheckout;
import org.eclipse.jgit.dircache.DirCacheCheckout.CheckoutMetadata;
import org.eclipse.jgit.dircache.DirCacheEntry;
import org.eclipse.jgit.errors.BinaryBlobException;
import org.eclipse.jgit.errors.CorruptObjectException;
import org.eclipse.jgit.errors.IncorrectObjectTypeException;
import org.eclipse.jgit.errors.IndexWriteException;
import org.eclipse.jgit.errors.MissingObjectException;
import org.eclipse.jgit.errors.NoWorkTreeException;
import org.eclipse.jgit.lib.Config;
import org.eclipse.jgit.lib.ConfigConstants;
import org.eclipse.jgit.lib.Constants;
import org.eclipse.jgit.lib.CoreConfig.EolStreamType;
import org.eclipse.jgit.lib.FileMode;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.ObjectInserter;
import org.eclipse.jgit.lib.ObjectLoader;
import org.eclipse.jgit.lib.Repository;
import org.eclipse.jgit.revwalk.RevTree;
import org.eclipse.jgit.storage.pack.PackConfig;
import org.eclipse.jgit.submodule.SubmoduleConflict;
import org.eclipse.jgit.treewalk.AbstractTreeIterator;
import org.eclipse.jgit.treewalk.CanonicalTreeParser;
import org.eclipse.jgit.treewalk.NameConflictTreeWalk;
import org.eclipse.jgit.treewalk.TreeWalk;
import org.eclipse.jgit.treewalk.TreeWalk.OperationType;
import org.eclipse.jgit.treewalk.WorkingTreeIterator;
import org.eclipse.jgit.treewalk.WorkingTreeOptions;
import org.eclipse.jgit.treewalk.filter.TreeFilter;
import org.eclipse.jgit.util.FS;
import org.eclipse.jgit.util.LfsFactory;
import org.eclipse.jgit.util.LfsFactory.LfsInputStream;
import org.eclipse.jgit.util.TemporaryBuffer;
import org.eclipse.jgit.util.io.EolStreamTypeUtil;


A three-way merger performing a content-merge if necessary

/**
 * A three-way merger performing a content-merge if necessary
 */
public class ResolveMerger extends ThreeWayMerger {
	
If the merge fails (means: not stopped because of unresolved conflicts)
this enum is used to explain why it failed

/**
	 * If the merge fails (means: not stopped because of unresolved conflicts)
	 * this enum is used to explain why it failed
	 */
	public enum MergeFailureReason {
		
the merge failed because of a dirty index 
/** the merge failed because of a dirty index */
		DIRTY_INDEX,
		
the merge failed because of a dirty workingtree 
/** the merge failed because of a dirty workingtree */
		DIRTY_WORKTREE,
		
the merge failed because of a file could not be deleted 
/** the merge failed because of a file could not be deleted */
		COULD_NOT_DELETE
	}

	
The tree walk which we'll iterate over to merge entries.

Since:3.4
/**
	 * The tree walk which we'll iterate over to merge entries.
	 *
	 * @since 3.4
	 */
	protected NameConflictTreeWalk tw;

	
string versions of a list of commit SHA1s

Since:3.0
/**
	 * string versions of a list of commit SHA1s
	 *
	 * @since 3.0
	 */
	protected String commitNames[];

	
Index of the base tree within the tree walk. 
Since:3.4
/**
	 * Index of the base tree within the {@link #tw tree walk}.
	 *
	 * @since 3.4
	 */
	protected static final int T_BASE = 0;

	
Index of our tree in withthe tree walk. 
Since:3.4
/**
	 * Index of our tree in withthe {@link #tw tree walk}.
	 *
	 * @since 3.4
	 */
	protected static final int T_OURS = 1;

	
Index of their tree within the tree walk. 
Since:3.4
/**
	 * Index of their tree within the {@link #tw tree walk}.
	 *
	 * @since 3.4
	 */
	protected static final int T_THEIRS = 2;

	
Index of the index tree within the tree walk. 
Since:3.4
/**
	 * Index of the index tree within the {@link #tw tree walk}.
	 *
	 * @since 3.4
	 */
	protected static final int T_INDEX = 3;

	
Index of the working directory tree within the tree walk. 
Since:3.4
/**
	 * Index of the working directory tree within the {@link #tw tree walk}.
	 *
	 * @since 3.4
	 */
	protected static final int T_FILE = 4;

	
Builder to update the cache during this merge.

Since:3.4
/**
	 * Builder to update the cache during this merge.
	 *
	 * @since 3.4
	 */
	protected DirCacheBuilder builder;

	
merge result as tree

Since:3.0
/**
	 * merge result as tree
	 *
	 * @since 3.0
	 */
	protected ObjectId resultTree;

	
Paths that could not be merged by this merger because of an unsolvable
conflict.

Since:3.4
/**
	 * Paths that could not be merged by this merger because of an unsolvable
	 * conflict.
	 *
	 * @since 3.4
	 */
	protected List<String> unmergedPaths = new ArrayList<>();

	
Files modified during this merge operation.

Since:3.4
/**
	 * Files modified during this merge operation.
	 *
	 * @since 3.4
	 */
	protected List<String> modifiedFiles = new LinkedList<>();

	
If the merger has nothing to do for a file but check it out at the end of
the operation, it can be added here.

Since:3.4
/**
	 * If the merger has nothing to do for a file but check it out at the end of
	 * the operation, it can be added here.
	 *
	 * @since 3.4
	 */
	protected Map<String, DirCacheEntry> toBeCheckedOut = new HashMap<>();

	
Paths in this list will be deleted from the local copy at the end of the
operation.

Since:3.4
/**
	 * Paths in this list will be deleted from the local copy at the end of the
	 * operation.
	 *
	 * @since 3.4
	 */
	protected List<String> toBeDeleted = new ArrayList<>();

	
Low-level textual merge results. Will be passed on to the callers in case
of conflicts.

Since:3.4
/**
	 * Low-level textual merge results. Will be passed on to the callers in case
	 * of conflicts.
	 *
	 * @since 3.4
	 */
	protected Map<String, MergeResult<? extends Sequence>> mergeResults = new HashMap<>();

	
Paths for which the merge failed altogether.

Since:3.4
/**
	 * Paths for which the merge failed altogether.
	 *
	 * @since 3.4
	 */
	protected Map<String, MergeFailureReason> failingPaths = new HashMap<>();

	
Updated as we merge entries of the tree walk. Tells us whether we should
recurse into the entry if it is a subtree.

Since:3.4
/**
	 * Updated as we merge entries of the tree walk. Tells us whether we should
	 * recurse into the entry if it is a subtree.
	 *
	 * @since 3.4
	 */
	protected boolean enterSubtree;

	
Set to true if this merge should work in-memory. The repos dircache and
workingtree are not touched by this method. Eventually needed files are
created as temporary files and a new empty, in-memory dircache will be
used instead the repo's one. Often used for bare repos where the repo
doesn't even have a workingtree and dircache.

Since:3.0
/**
	 * Set to true if this merge should work in-memory. The repos dircache and
	 * workingtree are not touched by this method. Eventually needed files are
	 * created as temporary files and a new empty, in-memory dircache will be
	 * used instead the repo's one. Often used for bare repos where the repo
	 * doesn't even have a workingtree and dircache.
	 * @since 3.0
	 */
	protected boolean inCore;

	
Set to true if this merger should use the default dircache of the
repository and should handle locking and unlocking of the dircache. If
this merger should work in-core or if an explicit dircache was specified
during construction then this field is set to false.

Since:3.0
/**
	 * Set to true if this merger should use the default dircache of the
	 * repository and should handle locking and unlocking of the dircache. If
	 * this merger should work in-core or if an explicit dircache was specified
	 * during construction then this field is set to false.
	 * @since 3.0
	 */
	protected boolean implicitDirCache;

	
Directory cache

Since:3.0
/**
	 * Directory cache
	 * @since 3.0
	 */
	protected DirCache dircache;

	
The iterator to access the working tree. If set to null this
merger will not touch the working tree.

Since:3.0
/**
	 * The iterator to access the working tree. If set to <code>null</code> this
	 * merger will not touch the working tree.
	 * @since 3.0
	 */
	protected WorkingTreeIterator workingTreeIterator;

	
our merge algorithm

Since:3.0
/**
	 * our merge algorithm
	 * @since 3.0
	 */
	protected MergeAlgorithm mergeAlgorithm;

	
The WorkingTreeOptions are needed to determine line endings for merged files. 
Since:4.11
/**
	 * The {@link WorkingTreeOptions} are needed to determine line endings for
	 * merged files.
	 *
	 * @since 4.11
	 */
	protected WorkingTreeOptions workingTreeOptions;

	
The size limit (bytes) which controls a file to be stored in Heap or LocalFile during the merge. 
/**
	 * The size limit (bytes) which controls a file to be stored in {@code Heap}
	 * or {@code LocalFile} during the merge.
	 */
	private int inCoreLimit;

	/**
	 * Keeps {@link CheckoutMetadata} for {@link #checkout()} and
	 * {@link #cleanUp()}.
	 */
	private Map<String, CheckoutMetadata> checkoutMetadata;

	private static MergeAlgorithm getMergeAlgorithm(Config config) {
		SupportedAlgorithm diffAlg = config.getEnum(
				CONFIG_DIFF_SECTION, null, CONFIG_KEY_ALGORITHM,
				HISTOGRAM);
		return new MergeAlgorithm(DiffAlgorithm.getAlgorithm(diffAlg));
	}

	private static int getInCoreLimit(Config config) {
		return config.getInt(
				ConfigConstants.CONFIG_MERGE_SECTION, ConfigConstants.CONFIG_KEY_IN_CORE_LIMIT, 10 << 20);
	}

	private static String[] defaultCommitNames() {
		return new String[] { "BASE", "OURS", "THEIRS" }; //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
	}

	private static final Attributes NO_ATTRIBUTES = new Attributes();

	
Constructor for ResolveMerger.

Params:
/**
	 * Constructor for ResolveMerger.
	 *
	 * @param local
	 *            the {@link org.eclipse.jgit.lib.Repository}.
	 * @param inCore
	 *            a boolean.
	 */
	protected ResolveMerger(Repository local, boolean inCore) {
		super(local);
		Config config = local.getConfig();
		mergeAlgorithm = getMergeAlgorithm(config);
		inCoreLimit = getInCoreLimit(config);
		commitNames = defaultCommitNames();
		this.inCore = inCore;

		if (inCore) {
			implicitDirCache = false;
			dircache = DirCache.newInCore();
		} else {
			implicitDirCache = true;
			workingTreeOptions = local.getConfig().get(WorkingTreeOptions.KEY);
		}
	}

	
Constructor for ResolveMerger.

Params:
/**
	 * Constructor for ResolveMerger.
	 *
	 * @param local
	 *            the {@link org.eclipse.jgit.lib.Repository}.
	 */
	protected ResolveMerger(Repository local) {
		this(local, false);
	}

	
Constructor for ResolveMerger.

Params:
  • inserter –  an ObjectInserter object.
  • config – 
           the repository configuration
Since:4.8
/**
	 * Constructor for ResolveMerger.
	 *
	 * @param inserter
	 *            an {@link org.eclipse.jgit.lib.ObjectInserter} object.
	 * @param config
	 *            the repository configuration
	 * @since 4.8
	 */
	protected ResolveMerger(ObjectInserter inserter, Config config) {
		super(inserter);
		mergeAlgorithm = getMergeAlgorithm(config);
		commitNames = defaultCommitNames();
		inCore = true;
		implicitDirCache = false;
		dircache = DirCache.newInCore();
	}

	
{@inheritDoc} 
/** {@inheritDoc} */
	@Override
	protected boolean mergeImpl() throws IOException {
		if (implicitDirCache) {
			dircache = nonNullRepo().lockDirCache();
		}
		if (!inCore) {
			checkoutMetadata = new HashMap<>();
		}
		try {
			return mergeTrees(mergeBase(), sourceTrees[0], sourceTrees[1],
					false);
		} finally {
			checkoutMetadata = null;
			if (implicitDirCache) {
				dircache.unlock();
			}
		}
	}

	private void checkout() throws NoWorkTreeException, IOException {
		// Iterate in reverse so that "folder/file" is deleted before
		// "folder". Otherwise this could result in a failing path because
		// of a non-empty directory, for which delete() would fail.
		for (int i = toBeDeleted.size() - 1; i >= 0; i--) {
			String fileName = toBeDeleted.get(i);
			File f = new File(nonNullRepo().getWorkTree(), fileName);
			if (!f.delete())
				if (!f.isDirectory())
					failingPaths.put(fileName,
							MergeFailureReason.COULD_NOT_DELETE);
			modifiedFiles.add(fileName);
		}
		for (Map.Entry<String, DirCacheEntry> entry : toBeCheckedOut
				.entrySet()) {
			DirCacheEntry cacheEntry = entry.getValue();
			if (cacheEntry.getFileMode() == FileMode.GITLINK) {
				new File(nonNullRepo().getWorkTree(), entry.getKey()).mkdirs();
			} else {
				DirCacheCheckout.checkoutEntry(db, cacheEntry, reader, false,
						checkoutMetadata.get(entry.getKey()));
				modifiedFiles.add(entry.getKey());
			}
		}
	}

	
Reverts the worktree after an unsuccessful merge. We know that for all
modified files the old content was in the old index and the index
contained only stage 0. In case if inCore operation just clear the
history of modified files.

Throws:
Since:3.4
/**
	 * Reverts the worktree after an unsuccessful merge. We know that for all
	 * modified files the old content was in the old index and the index
	 * contained only stage 0. In case if inCore operation just clear the
	 * history of modified files.
	 *
	 * @throws java.io.IOException
	 * @throws org.eclipse.jgit.errors.CorruptObjectException
	 * @throws org.eclipse.jgit.errors.NoWorkTreeException
	 * @since 3.4
	 */
	protected void cleanUp() throws NoWorkTreeException,
			CorruptObjectException,
			IOException {
		if (inCore) {
			modifiedFiles.clear();
			return;
		}

		DirCache dc = nonNullRepo().readDirCache();
		Iterator<String> mpathsIt=modifiedFiles.iterator();
		while(mpathsIt.hasNext()) {
			String mpath = mpathsIt.next();
			DirCacheEntry entry = dc.getEntry(mpath);
			if (entry != null) {
				DirCacheCheckout.checkoutEntry(db, entry, reader, false,
						checkoutMetadata.get(mpath));
			}
			mpathsIt.remove();
		}
	}

	
adds a new path with the specified stage to the index builder

Params:
  • path – 
  • p – 
  • stage – 
  • lastMod – 
  • len – 
Returns:the entry which was added to the index
/**
	 * adds a new path with the specified stage to the index builder
	 *
	 * @param path
	 * @param p
	 * @param stage
	 * @param lastMod
	 * @param len
	 * @return the entry which was added to the index
	 */
	private DirCacheEntry add(byte[] path, CanonicalTreeParser p, int stage,
			Instant lastMod, long len) {
		if (p != null && !p.getEntryFileMode().equals(FileMode.TREE)) {
			DirCacheEntry e = new DirCacheEntry(path, stage);
			e.setFileMode(p.getEntryFileMode());
			e.setObjectId(p.getEntryObjectId());
			e.setLastModified(lastMod);
			e.setLength(len);
			builder.add(e);
			return e;
		}
		return null;
	}

	
adds a entry to the index builder which is a copy of the specified
DirCacheEntry

Params:
  • e – 
           the entry which should be copied
Returns:the entry which was added to the index
/**
	 * adds a entry to the index builder which is a copy of the specified
	 * DirCacheEntry
	 *
	 * @param e
	 *            the entry which should be copied
	 *
	 * @return the entry which was added to the index
	 */
	private DirCacheEntry keep(DirCacheEntry e) {
		DirCacheEntry newEntry = new DirCacheEntry(e.getRawPath(),
				e.getStage());
		newEntry.setFileMode(e.getFileMode());
		newEntry.setObjectId(e.getObjectId());
		newEntry.setLastModified(e.getLastModifiedInstant());
		newEntry.setLength(e.getLength());
		builder.add(newEntry);
		return newEntry;
	}

	
Remembers the CheckoutMetadata for the given path; it may be needed in checkout() or in cleanUp(). 
Params:
  • path – 
           of the current node
  • attributes – 
           for the current node
Throws:
  • IOException – 
            if the smudge filter cannot be determined
Since:5.1
/**
	 * Remembers the {@link CheckoutMetadata} for the given path; it may be
	 * needed in {@link #checkout()} or in {@link #cleanUp()}.
	 *
	 * @param path
	 *            of the current node
	 * @param attributes
	 *            for the current node
	 * @throws IOException
	 *             if the smudge filter cannot be determined
	 * @since 5.1
	 */
	protected void addCheckoutMetadata(String path, Attributes attributes)
			throws IOException {
		if (checkoutMetadata != null) {
			EolStreamType eol = EolStreamTypeUtil.detectStreamType(
					OperationType.CHECKOUT_OP, workingTreeOptions, attributes);
			CheckoutMetadata data = new CheckoutMetadata(eol,
					tw.getFilterCommand(Constants.ATTR_FILTER_TYPE_SMUDGE));
			checkoutMetadata.put(path, data);
		}
	}

	
Adds a DirCacheEntry for direct checkout and remembers its CheckoutMetadata. 
Params:
  • path – 
           of the entry
  • entry – 
           to add
  • attributes – 
           for the current entry
Throws:
Since:5.1
/**
	 * Adds a {@link DirCacheEntry} for direct checkout and remembers its
	 * {@link CheckoutMetadata}.
	 *
	 * @param path
	 *            of the entry
	 * @param entry
	 *            to add
	 * @param attributes
	 *            for the current entry
	 * @throws IOException
	 *             if the {@link CheckoutMetadata} cannot be determined
	 * @since 5.1
	 */
	protected void addToCheckout(String path, DirCacheEntry entry,
			Attributes attributes) throws IOException {
		toBeCheckedOut.put(path, entry);
		addCheckoutMetadata(path, attributes);
	}

	
Remember a path for deletion, and remember its CheckoutMetadata in case it has to be restored in cleanUp(). 
Params:
  • path – 
           of the entry
  • isFile – 
           whether it is a file
  • attributes – 
           for the entry
Throws:
Since:5.1
/**
	 * Remember a path for deletion, and remember its {@link CheckoutMetadata}
	 * in case it has to be restored in {@link #cleanUp()}.
	 *
	 * @param path
	 *            of the entry
	 * @param isFile
	 *            whether it is a file
	 * @param attributes
	 *            for the entry
	 * @throws IOException
	 *             if the {@link CheckoutMetadata} cannot be determined
	 * @since 5.1
	 */
	protected void addDeletion(String path, boolean isFile,
			Attributes attributes) throws IOException {
		toBeDeleted.add(path);
		if (isFile) {
			addCheckoutMetadata(path, attributes);
		}
	}

	
Processes one path and tries to merge taking git attributes in account.
This method will do all trivial (not content) merges and will also detect
if a merge will fail. The merge will fail when one of the following is
true

    

  • the index entry does not match the entry in ours. When merging one
branch into the current HEAD, ours will point to HEAD and theirs will
point to the other branch. It is assumed that the index matches the HEAD
because it will only not match HEAD if it was populated before the merge
operation. But the merge commit should not accidentally contain
modifications done before the merge. Check the git read-tree documentation for further explanations.
    • 

  • A conflict was detected and the working-tree file is dirty. When a
conflict is detected the content-merge algorithm will try to write a
merged version into the working-tree. If the file is dirty we would
override unsaved data.
    • 



Params:
  • base – 
           the common base for ours and theirs
  • ours – 
           the ours side of the merge. When merging a branch into the
           HEAD ours will point to HEAD
  • theirs – 
           the theirs side of the merge. When merging a branch into the
           current HEAD theirs will point to the branch which is merged
           into HEAD.
  • index – 
           the index entry
  • work – 
           the file in the working tree
  • ignoreConflicts –  see mergeTrees(AbstractTreeIterator, RevTree, RevTree, boolean)
  • attributes – 
           the attributes defined for this entry
Throws:
Returns:false if the merge will fail because the index entry
        didn't match ours or the working-dir file was dirty and a
        conflict occurred
Since:4.9
/**
	 * Processes one path and tries to merge taking git attributes in account.
	 * This method will do all trivial (not content) merges and will also detect
	 * if a merge will fail. The merge will fail when one of the following is
	 * true
	 * <ul>
	 * <li>the index entry does not match the entry in ours. When merging one
	 * branch into the current HEAD, ours will point to HEAD and theirs will
	 * point to the other branch. It is assumed that the index matches the HEAD
	 * because it will only not match HEAD if it was populated before the merge
	 * operation. But the merge commit should not accidentally contain
	 * modifications done before the merge. Check the <a href=
	 * "http://www.kernel.org/pub/software/scm/git/docs/git-read-tree.html#_3_way_merge"
	 * >git read-tree</a> documentation for further explanations.</li>
	 * <li>A conflict was detected and the working-tree file is dirty. When a
	 * conflict is detected the content-merge algorithm will try to write a
	 * merged version into the working-tree. If the file is dirty we would
	 * override unsaved data.</li>
	 * </ul>
	 *
	 * @param base
	 *            the common base for ours and theirs
	 * @param ours
	 *            the ours side of the merge. When merging a branch into the
	 *            HEAD ours will point to HEAD
	 * @param theirs
	 *            the theirs side of the merge. When merging a branch into the
	 *            current HEAD theirs will point to the branch which is merged
	 *            into HEAD.
	 * @param index
	 *            the index entry
	 * @param work
	 *            the file in the working tree
	 * @param ignoreConflicts
	 *            see
	 *            {@link org.eclipse.jgit.merge.ResolveMerger#mergeTrees(AbstractTreeIterator, RevTree, RevTree, boolean)}
	 * @param attributes
	 *            the attributes defined for this entry
	 * @return <code>false</code> if the merge will fail because the index entry
	 *         didn't match ours or the working-dir file was dirty and a
	 *         conflict occurred
	 * @throws org.eclipse.jgit.errors.MissingObjectException
	 * @throws org.eclipse.jgit.errors.IncorrectObjectTypeException
	 * @throws org.eclipse.jgit.errors.CorruptObjectException
	 * @throws java.io.IOException
	 * @since 4.9
	 */
	protected boolean processEntry(CanonicalTreeParser base,
			CanonicalTreeParser ours, CanonicalTreeParser theirs,
			DirCacheBuildIterator index, WorkingTreeIterator work,
			boolean ignoreConflicts, Attributes attributes)
			throws MissingObjectException, IncorrectObjectTypeException,
			CorruptObjectException, IOException {
		enterSubtree = true;
		final int modeO = tw.getRawMode(T_OURS);
		final int modeT = tw.getRawMode(T_THEIRS);
		final int modeB = tw.getRawMode(T_BASE);

		if (modeO == 0 && modeT == 0 && modeB == 0)
			// File is either untracked or new, staged but uncommitted
			return true;

		if (isIndexDirty())
			return false;

		DirCacheEntry ourDce = null;

		if (index == null || index.getDirCacheEntry() == null) {
			// create a fake DCE, but only if ours is valid. ours is kept only
			// in case it is valid, so a null ourDce is ok in all other cases.
			if (nonTree(modeO)) {
				ourDce = new DirCacheEntry(tw.getRawPath());
				ourDce.setObjectId(tw.getObjectId(T_OURS));
				ourDce.setFileMode(tw.getFileMode(T_OURS));
			}
		} else {
			ourDce = index.getDirCacheEntry();
		}

		if (nonTree(modeO) && nonTree(modeT) && tw.idEqual(T_OURS, T_THEIRS)) {
			// OURS and THEIRS have equal content. Check the file mode
			if (modeO == modeT) {
				// content and mode of OURS and THEIRS are equal: it doesn't
				// matter which one we choose. OURS is chosen. Since the index
				// is clean (the index matches already OURS) we can keep the existing one
				keep(ourDce);
				// no checkout needed!
				return true;
			} else {
				// same content but different mode on OURS and THEIRS.
				// Try to merge the mode and report an error if this is
				// not possible.
				int newMode = mergeFileModes(modeB, modeO, modeT);
				if (newMode != FileMode.MISSING.getBits()) {
					if (newMode == modeO)
						// ours version is preferred
						keep(ourDce);
					else {
						// the preferred version THEIRS has a different mode
						// than ours. Check it out!
						if (isWorktreeDirty(work, ourDce))
							return false;
						// we know about length and lastMod only after we have written the new content.
						// This will happen later. Set these values to 0 for know.
						DirCacheEntry e = add(tw.getRawPath(), theirs,
								DirCacheEntry.STAGE_0, EPOCH, 0);
						addToCheckout(tw.getPathString(), e, attributes);
					}
					return true;
				} else {
					// FileModes are not mergeable. We found a conflict on modes.
					// For conflicting entries we don't know lastModified and length.
					add(tw.getRawPath(), base, DirCacheEntry.STAGE_1, EPOCH, 0);
					add(tw.getRawPath(), ours, DirCacheEntry.STAGE_2, EPOCH, 0);
					add(tw.getRawPath(), theirs, DirCacheEntry.STAGE_3, EPOCH,
							0);
					unmergedPaths.add(tw.getPathString());
					mergeResults.put(
							tw.getPathString(),
							new MergeResult<>(Collections
									.<RawText> emptyList()));
				}
				return true;
			}
		}

		if (modeB == modeT && tw.idEqual(T_BASE, T_THEIRS)) {
			// THEIRS was not changed compared to BASE. All changes must be in
			// OURS. OURS is chosen. We can keep the existing entry.
			if (ourDce != null)
				keep(ourDce);
			// no checkout needed!
			return true;
		}

		if (modeB == modeO && tw.idEqual(T_BASE, T_OURS)) {
			// OURS was not changed compared to BASE. All changes must be in
			// THEIRS. THEIRS is chosen.

			// Check worktree before checking out THEIRS
			if (isWorktreeDirty(work, ourDce))
				return false;
			if (nonTree(modeT)) {
				// we know about length and lastMod only after we have written
				// the new content.
				// This will happen later. Set these values to 0 for know.
				DirCacheEntry e = add(tw.getRawPath(), theirs,
						DirCacheEntry.STAGE_0, EPOCH, 0);
				if (e != null) {
					addToCheckout(tw.getPathString(), e, attributes);
				}
				return true;
			} else {
				// we want THEIRS ... but THEIRS contains a folder or the
				// deletion of the path. Delete what's in the working tree,
				// which we know to be clean.
				if (tw.getTreeCount() > T_FILE && tw.getRawMode(T_FILE) == 0) {
					// Not present in working tree, so nothing to delete
					return true;
				}
				if (modeT != 0 && modeT == modeB) {
					// Base, ours, and theirs all contain a folder: don't delete
					return true;
				}
				addDeletion(tw.getPathString(), nonTree(modeO), attributes);
				return true;
			}
		}

		if (tw.isSubtree()) {
			// file/folder conflicts: here I want to detect only file/folder
			// conflict between ours and theirs. file/folder conflicts between
			// base/index/workingTree and something else are not relevant or
			// detected later
			if (nonTree(modeO) && !nonTree(modeT)) {
				if (nonTree(modeB))
					add(tw.getRawPath(), base, DirCacheEntry.STAGE_1, EPOCH, 0);
				add(tw.getRawPath(), ours, DirCacheEntry.STAGE_2, EPOCH, 0);
				unmergedPaths.add(tw.getPathString());
				enterSubtree = false;
				return true;
			}
			if (nonTree(modeT) && !nonTree(modeO)) {
				if (nonTree(modeB))
					add(tw.getRawPath(), base, DirCacheEntry.STAGE_1, EPOCH, 0);
				add(tw.getRawPath(), theirs, DirCacheEntry.STAGE_3, EPOCH, 0);
				unmergedPaths.add(tw.getPathString());
				enterSubtree = false;
				return true;
			}

			// ours and theirs are both folders or both files (and treewalk
			// tells us we are in a subtree because of index or working-dir).
			// If they are both folders no content-merge is required - we can
			// return here.
			if (!nonTree(modeO))
				return true;

			// ours and theirs are both files, just fall out of the if block
			// and do the content merge
		}

		if (nonTree(modeO) && nonTree(modeT)) {
			// Check worktree before modifying files
			boolean worktreeDirty = isWorktreeDirty(work, ourDce);
			if (!attributes.canBeContentMerged() && worktreeDirty) {
				return false;
			}

			boolean gitlinkConflict = isGitLink(modeO) || isGitLink(modeT);
			// Don't attempt to resolve submodule link conflicts
			if (gitlinkConflict || !attributes.canBeContentMerged()) {
				add(tw.getRawPath(), base, DirCacheEntry.STAGE_1, EPOCH, 0);
				add(tw.getRawPath(), ours, DirCacheEntry.STAGE_2, EPOCH, 0);
				add(tw.getRawPath(), theirs, DirCacheEntry.STAGE_3, EPOCH, 0);

				if (gitlinkConflict) {
					MergeResult<SubmoduleConflict> result = new MergeResult<>(
							Arrays.asList(
									new SubmoduleConflict(base == null ? null
											: base.getEntryObjectId()),
									new SubmoduleConflict(ours == null ? null
											: ours.getEntryObjectId()),
									new SubmoduleConflict(theirs == null ? null
											: theirs.getEntryObjectId())));
					result.setContainsConflicts(true);
					mergeResults.put(tw.getPathString(), result);
					if (!ignoreConflicts) {
						unmergedPaths.add(tw.getPathString());
					}
				} else {
					// attribute merge issues are conflicts but not failures
					unmergedPaths.add(tw.getPathString());
				}
				return true;
			}

			// Check worktree before modifying files
			if (worktreeDirty) {
				return false;
			}

			MergeResult<RawText> result = contentMerge(base, ours, theirs,
					attributes);
			if (ignoreConflicts) {
				result.setContainsConflicts(false);
			}
			updateIndex(base, ours, theirs, result, attributes);
			String currentPath = tw.getPathString();
			if (result.containsConflicts() && !ignoreConflicts) {
				unmergedPaths.add(currentPath);
			}
			modifiedFiles.add(currentPath);
			addCheckoutMetadata(currentPath, attributes);
		} else if (modeO != modeT) {
			// OURS or THEIRS has been deleted
			if (((modeO != 0 && !tw.idEqual(T_BASE, T_OURS)) || (modeT != 0 && !tw
					.idEqual(T_BASE, T_THEIRS)))) {
				MergeResult<RawText> result = contentMerge(base, ours, theirs,
						attributes);

				add(tw.getRawPath(), base, DirCacheEntry.STAGE_1, EPOCH, 0);
				add(tw.getRawPath(), ours, DirCacheEntry.STAGE_2, EPOCH, 0);
				DirCacheEntry e = add(tw.getRawPath(), theirs,
						DirCacheEntry.STAGE_3, EPOCH, 0);

				// OURS was deleted checkout THEIRS
				if (modeO == 0) {
					// Check worktree before checking out THEIRS
					if (isWorktreeDirty(work, ourDce))
						return false;
					if (nonTree(modeT)) {
						if (e != null) {
							addToCheckout(tw.getPathString(), e, attributes);
						}
					}
				}

				unmergedPaths.add(tw.getPathString());

				// generate a MergeResult for the deleted file
				mergeResults.put(tw.getPathString(), result);
			}
		}
		return true;
	}

	
Does the content merge. The three texts base, ours and theirs are specified with CanonicalTreeParser. If any of the parsers is specified as null then an empty text will be used instead.

Params:
  • base – 
  • ours – 
  • theirs – 
  • attributes – 
Throws:
Returns:the result of the content merge
/**
	 * Does the content merge. The three texts base, ours and theirs are
	 * specified with {@link CanonicalTreeParser}. If any of the parsers is
	 * specified as <code>null</code> then an empty text will be used instead.
	 *
	 * @param base
	 * @param ours
	 * @param theirs
	 * @param attributes
	 *
	 * @return the result of the content merge
	 * @throws IOException
	 */
	private MergeResult<RawText> contentMerge(CanonicalTreeParser base,
			CanonicalTreeParser ours, CanonicalTreeParser theirs,
			Attributes attributes)
			throws IOException {
		RawText baseText;
		RawText ourText;
		RawText theirsText;

		try {
			baseText = base == null ? RawText.EMPTY_TEXT : getRawText(
							base.getEntryObjectId(), attributes);
			ourText = ours == null ? RawText.EMPTY_TEXT : getRawText(
							ours.getEntryObjectId(), attributes);
			theirsText = theirs == null ? RawText.EMPTY_TEXT : getRawText(
							theirs.getEntryObjectId(), attributes);
		} catch (BinaryBlobException e) {
			MergeResult<RawText> r = new MergeResult<>(Collections.<RawText>emptyList());
			r.setContainsConflicts(true);
			return r;
		}
		return (mergeAlgorithm.merge(RawTextComparator.DEFAULT, baseText,
				ourText, theirsText));
	}

	private boolean isIndexDirty() {
		if (inCore)
			return false;

		final int modeI = tw.getRawMode(T_INDEX);
		final int modeO = tw.getRawMode(T_OURS);

		// Index entry has to match ours to be considered clean
		final boolean isDirty = nonTree(modeI)
				&& !(modeO == modeI && tw.idEqual(T_INDEX, T_OURS));
		if (isDirty)
			failingPaths
					.put(tw.getPathString(), MergeFailureReason.DIRTY_INDEX);
		return isDirty;
	}

	private boolean isWorktreeDirty(WorkingTreeIterator work,
			DirCacheEntry ourDce) throws IOException {
		if (work == null)
			return false;

		final int modeF = tw.getRawMode(T_FILE);
		final int modeO = tw.getRawMode(T_OURS);

		// Worktree entry has to match ours to be considered clean
		boolean isDirty;
		if (ourDce != null)
			isDirty = work.isModified(ourDce, true, reader);
		else {
			isDirty = work.isModeDifferent(modeO);
			if (!isDirty && nonTree(modeF))
				isDirty = !tw.idEqual(T_FILE, T_OURS);
		}

		// Ignore existing empty directories
		if (isDirty && modeF == FileMode.TYPE_TREE
				&& modeO == FileMode.TYPE_MISSING)
			isDirty = false;
		if (isDirty)
			failingPaths.put(tw.getPathString(),
					MergeFailureReason.DIRTY_WORKTREE);
		return isDirty;
	}

	
Updates the index after a content merge has happened. If no conflict has
occurred this includes persisting the merged content to the object
database. In case of conflicts this method takes care to write the
correct stages to the index.

Params:
  • base – 
  • ours – 
  • theirs – 
  • result – 
  • attributes – 
Throws:
/**
	 * Updates the index after a content merge has happened. If no conflict has
	 * occurred this includes persisting the merged content to the object
	 * database. In case of conflicts this method takes care to write the
	 * correct stages to the index.
	 *
	 * @param base
	 * @param ours
	 * @param theirs
	 * @param result
	 * @param attributes
	 * @throws FileNotFoundException
	 * @throws IOException
	 */
	private void updateIndex(CanonicalTreeParser base,
			CanonicalTreeParser ours, CanonicalTreeParser theirs,
			MergeResult<RawText> result, Attributes attributes)
			throws FileNotFoundException,
			IOException {
		TemporaryBuffer rawMerged = null;
		try {
			rawMerged = doMerge(result);
			File mergedFile = inCore ? null
					: writeMergedFile(rawMerged, attributes);
			if (result.containsConflicts()) {
				// A conflict occurred, the file will contain conflict markers
				// the index will be populated with the three stages and the
				// workdir (if used) contains the halfway merged content.
				add(tw.getRawPath(), base, DirCacheEntry.STAGE_1, EPOCH, 0);
				add(tw.getRawPath(), ours, DirCacheEntry.STAGE_2, EPOCH, 0);
				add(tw.getRawPath(), theirs, DirCacheEntry.STAGE_3, EPOCH, 0);
				mergeResults.put(tw.getPathString(), result);
				return;
			}

			// No conflict occurred, the file will contain fully merged content.
			// The index will be populated with the new merged version.
			DirCacheEntry dce = new DirCacheEntry(tw.getPathString());

			// Set the mode for the new content. Fall back to REGULAR_FILE if
			// we can't merge modes of OURS and THEIRS.
			int newMode = mergeFileModes(tw.getRawMode(0), tw.getRawMode(1),
					tw.getRawMode(2));
			dce.setFileMode(newMode == FileMode.MISSING.getBits()
					? FileMode.REGULAR_FILE : FileMode.fromBits(newMode));
			if (mergedFile != null) {
				dce.setLastModified(
						nonNullRepo().getFS().lastModifiedInstant(mergedFile));
				dce.setLength((int) mergedFile.length());
			}
			dce.setObjectId(insertMergeResult(rawMerged, attributes));
			builder.add(dce);
		} finally {
			if (rawMerged != null) {
				rawMerged.destroy();
			}
		}
	}

	
Writes merged file content to the working tree.

Params:
  • rawMerged – 
           the raw merged content
  • attributes – 
           the files .gitattributes entries
Throws:
Returns:the working tree file to which the merged content was written.
/**
	 * Writes merged file content to the working tree.
	 *
	 * @param rawMerged
	 *            the raw merged content
	 * @param attributes
	 *            the files .gitattributes entries
	 * @return the working tree file to which the merged content was written.
	 * @throws FileNotFoundException
	 * @throws IOException
	 */
	private File writeMergedFile(TemporaryBuffer rawMerged,
			Attributes attributes)
			throws FileNotFoundException, IOException {
		File workTree = nonNullRepo().getWorkTree();
		FS fs = nonNullRepo().getFS();
		File of = new File(workTree, tw.getPathString());
		File parentFolder = of.getParentFile();
		if (!fs.exists(parentFolder)) {
			parentFolder.mkdirs();
		}
		EolStreamType streamType = EolStreamTypeUtil.detectStreamType(
				OperationType.CHECKOUT_OP, workingTreeOptions,
				attributes);
		try (OutputStream os = EolStreamTypeUtil.wrapOutputStream(
				new BufferedOutputStream(new FileOutputStream(of)),
				streamType)) {
			rawMerged.writeTo(os, null);
		}
		return of;
	}

	private TemporaryBuffer doMerge(MergeResult<RawText> result)
			throws IOException {
		TemporaryBuffer.LocalFile buf = new TemporaryBuffer.LocalFile(
				db != null ? nonNullRepo().getDirectory() : null, inCoreLimit);
		boolean success = false;
		try {
			new MergeFormatter().formatMerge(buf, result,
					Arrays.asList(commitNames), UTF_8);
			buf.close();
			success = true;
		} finally {
			if (!success) {
				buf.destroy();
			}
		}
		return buf;
	}

	private ObjectId insertMergeResult(TemporaryBuffer buf,
			Attributes attributes) throws IOException {
		InputStream in = buf.openInputStream();
		try (LfsInputStream is = LfsFactory.getInstance().applyCleanFilter(
				getRepository(), in,
				buf.length(), attributes.get(Constants.ATTR_MERGE))) {
			return getObjectInserter().insert(OBJ_BLOB, is.getLength(), is);
		}
	}

	
Try to merge filemodes. If only ours or theirs have changed the mode (compared to base) we choose that one. If ours and theirs have equal modes return that one. If also that is not the case the modes are not mergeable. Return FileMode.MISSING int that case. 
Params:
  • modeB – 
           filemode found in BASE
  • modeO – 
           filemode found in OURS
  • modeT – 
           filemode found in THEIRS
Returns:the merged filemode or FileMode.MISSING in case of a conflict
/**
	 * Try to merge filemodes. If only ours or theirs have changed the mode
	 * (compared to base) we choose that one. If ours and theirs have equal
	 * modes return that one. If also that is not the case the modes are not
	 * mergeable. Return {@link FileMode#MISSING} int that case.
	 *
	 * @param modeB
	 *            filemode found in BASE
	 * @param modeO
	 *            filemode found in OURS
	 * @param modeT
	 *            filemode found in THEIRS
	 *
	 * @return the merged filemode or {@link FileMode#MISSING} in case of a
	 *         conflict
	 */
	private int mergeFileModes(int modeB, int modeO, int modeT) {
		if (modeO == modeT)
			return modeO;
		if (modeB == modeO)
			// Base equal to Ours -> chooses Theirs if that is not missing
			return (modeT == FileMode.MISSING.getBits()) ? modeO : modeT;
		if (modeB == modeT)
			// Base equal to Theirs -> chooses Ours if that is not missing
			return (modeO == FileMode.MISSING.getBits()) ? modeT : modeO;
		return FileMode.MISSING.getBits();
	}

	private RawText getRawText(ObjectId id,
			Attributes attributes)
			throws IOException, BinaryBlobException {
		if (id.equals(ObjectId.zeroId()))
			return new RawText(new byte[] {});

		ObjectLoader loader = LfsFactory.getInstance().applySmudgeFilter(
				getRepository(), reader.open(id, OBJ_BLOB),
				attributes.get(Constants.ATTR_MERGE));
		int threshold = PackConfig.DEFAULT_BIG_FILE_THRESHOLD;
		return RawText.load(loader, threshold);
	}

	private static boolean nonTree(int mode) {
		return mode != 0 && !FileMode.TREE.equals(mode);
	}

	private static boolean isGitLink(int mode) {
		return FileMode.GITLINK.equals(mode);
	}

	
{@inheritDoc} 
/** {@inheritDoc} */
	@Override
	public ObjectId getResultTreeId() {
		return (resultTree == null) ? null : resultTree.toObjectId();
	}

	
Set the names of the commits as they would appear in conflict markers

Params:
  • commitNames – 
           the names of the commits as they would appear in conflict
           markers
/**
	 * Set the names of the commits as they would appear in conflict markers
	 *
	 * @param commitNames
	 *            the names of the commits as they would appear in conflict
	 *            markers
	 */
	public void setCommitNames(String[] commitNames) {
		this.commitNames = commitNames;
	}

	
Get the names of the commits as they would appear in conflict markers.

Returns:the names of the commits as they would appear in conflict
        markers.
/**
	 * Get the names of the commits as they would appear in conflict markers.
	 *
	 * @return the names of the commits as they would appear in conflict
	 *         markers.
	 */
	public String[] getCommitNames() {
		return commitNames;
	}

	
Get the paths with conflicts. This is a subset of the files listed by getModifiedFiles() 
Returns:the paths with conflicts. This is a subset of the files listed by getModifiedFiles()
/**
	 * Get the paths with conflicts. This is a subset of the files listed by
	 * {@link #getModifiedFiles()}
	 *
	 * @return the paths with conflicts. This is a subset of the files listed by
	 *         {@link #getModifiedFiles()}
	 */
	public List<String> getUnmergedPaths() {
		return unmergedPaths;
	}

	
Get the paths of files which have been modified by this merge.

Returns:the paths of files which have been modified by this merge. A file will be modified if a content-merge works on this path or if the merge algorithm decides to take the theirs-version. This is a superset of the files listed by getUnmergedPaths().
/**
	 * Get the paths of files which have been modified by this merge.
	 *
	 * @return the paths of files which have been modified by this merge. A file
	 *         will be modified if a content-merge works on this path or if the
	 *         merge algorithm decides to take the theirs-version. This is a
	 *         superset of the files listed by {@link #getUnmergedPaths()}.
	 */
	public List<String> getModifiedFiles() {
		return modifiedFiles;
	}

	
Get a map which maps the paths of files which have to be checked out
because the merge created new fully-merged content for this file into the
index.

Returns:a map which maps the paths of files which have to be checked out
        because the merge created new fully-merged content for this file
        into the index. This means: the merge wrote a new stage 0 entry
        for this path.
/**
	 * Get a map which maps the paths of files which have to be checked out
	 * because the merge created new fully-merged content for this file into the
	 * index.
	 *
	 * @return a map which maps the paths of files which have to be checked out
	 *         because the merge created new fully-merged content for this file
	 *         into the index. This means: the merge wrote a new stage 0 entry
	 *         for this path.
	 */
	public Map<String, DirCacheEntry> getToBeCheckedOut() {
		return toBeCheckedOut;
	}

	
Get the mergeResults

Returns:the mergeResults
/**
	 * Get the mergeResults
	 *
	 * @return the mergeResults
	 */
	public Map<String, MergeResult<? extends Sequence>> getMergeResults() {
		return mergeResults;
	}

	
Get list of paths causing this merge to fail (not stopped because of a
conflict).

Returns:lists paths causing this merge to fail (not stopped because of a
        conflict). null is returned if this merge didn't
        fail.
/**
	 * Get list of paths causing this merge to fail (not stopped because of a
	 * conflict).
	 *
	 * @return lists paths causing this merge to fail (not stopped because of a
	 *         conflict). <code>null</code> is returned if this merge didn't
	 *         fail.
	 */
	public Map<String, MergeFailureReason> getFailingPaths() {
		return failingPaths.isEmpty() ? null : failingPaths;
	}

	
Returns whether this merge failed (i.e. not stopped because of a
conflict)

Returns:true if a failure occurred, false
        otherwise
/**
	 * Returns whether this merge failed (i.e. not stopped because of a
	 * conflict)
	 *
	 * @return <code>true</code> if a failure occurred, <code>false</code>
	 *         otherwise
	 */
	public boolean failed() {
		return !failingPaths.isEmpty();
	}

	
Sets the DirCache which shall be used by this merger. If the DirCache is not set explicitly and if this merger doesn't work in-core, this merger will implicitly get and lock a default DirCache. If the DirCache is explicitly set the caller is responsible to lock it in advance. Finally the merger will call DirCache.commit() which requires that the DirCache is locked. If the mergeImpl() returns without throwing an exception the lock will be released. In case of exceptions the caller is responsible to release the lock. 
Params:
  • dc – 
           the DirCache to set
/**
	 * Sets the DirCache which shall be used by this merger. If the DirCache is
	 * not set explicitly and if this merger doesn't work in-core, this merger
	 * will implicitly get and lock a default DirCache. If the DirCache is
	 * explicitly set the caller is responsible to lock it in advance. Finally
	 * the merger will call {@link org.eclipse.jgit.dircache.DirCache#commit()}
	 * which requires that the DirCache is locked. If the {@link #mergeImpl()}
	 * returns without throwing an exception the lock will be released. In case
	 * of exceptions the caller is responsible to release the lock.
	 *
	 * @param dc
	 *            the DirCache to set
	 */
	public void setDirCache(DirCache dc) {
		this.dircache = dc;
		implicitDirCache = false;
	}

	
Sets the WorkingTreeIterator to be used by this merger. If no
WorkingTreeIterator is set this merger will ignore the working tree and
fail if a content merge is necessary.


TODO: enhance WorkingTreeIterator to support write operations. Then this
merger will be able to merge with a different working tree abstraction.

Params:
  • workingTreeIterator – 
           the workingTreeIt to set
/**
	 * Sets the WorkingTreeIterator to be used by this merger. If no
	 * WorkingTreeIterator is set this merger will ignore the working tree and
	 * fail if a content merge is necessary.
	 * <p>
	 * TODO: enhance WorkingTreeIterator to support write operations. Then this
	 * merger will be able to merge with a different working tree abstraction.
	 *
	 * @param workingTreeIterator
	 *            the workingTreeIt to set
	 */
	public void setWorkingTreeIterator(WorkingTreeIterator workingTreeIterator) {
		this.workingTreeIterator = workingTreeIterator;
	}


	
The resolve conflict way of three way merging

Params:
  • baseTree –  a AbstractTreeIterator object.
  • headTree –  a RevTree object.
  • mergeTree –  a RevTree object.
  • ignoreConflicts – 
           Controls what to do in case a content-merge is done and a
           conflict is detected. The default setting for this should be
           false. In this case the working tree file is
           filled with new content (containing conflict markers) and the
           index is filled with multiple stages containing BASE, OURS and
           THEIRS content. Having such non-0 stages is the sign to git
           tools that there are still conflicts for that path.
           
    
           If true is specified the behavior is different. In case a conflict is detected the working tree file is again filled with new content (containing conflict markers). But also stage 0 of the index is filled with that content. No other stages are filled. Means: there is no conflict on that path but the new content (including conflict markers) is stored as successful merge result. This is needed in the context of RecursiveMerger where when determining merge bases we don't want to deal with content-merge conflicts.
Throws:
Returns:whether the trees merged cleanly
Since:3.5
/**
	 * The resolve conflict way of three way merging
	 *
	 * @param baseTree
	 *            a {@link org.eclipse.jgit.treewalk.AbstractTreeIterator}
	 *            object.
	 * @param headTree
	 *            a {@link org.eclipse.jgit.revwalk.RevTree} object.
	 * @param mergeTree
	 *            a {@link org.eclipse.jgit.revwalk.RevTree} object.
	 * @param ignoreConflicts
	 *            Controls what to do in case a content-merge is done and a
	 *            conflict is detected. The default setting for this should be
	 *            <code>false</code>. In this case the working tree file is
	 *            filled with new content (containing conflict markers) and the
	 *            index is filled with multiple stages containing BASE, OURS and
	 *            THEIRS content. Having such non-0 stages is the sign to git
	 *            tools that there are still conflicts for that path.
	 *            <p>
	 *            If <code>true</code> is specified the behavior is different.
	 *            In case a conflict is detected the working tree file is again
	 *            filled with new content (containing conflict markers). But
	 *            also stage 0 of the index is filled with that content. No
	 *            other stages are filled. Means: there is no conflict on that
	 *            path but the new content (including conflict markers) is
	 *            stored as successful merge result. This is needed in the
	 *            context of {@link org.eclipse.jgit.merge.RecursiveMerger}
	 *            where when determining merge bases we don't want to deal with
	 *            content-merge conflicts.
	 * @return whether the trees merged cleanly
	 * @throws java.io.IOException
	 * @since 3.5
	 */
	protected boolean mergeTrees(AbstractTreeIterator baseTree,
			RevTree headTree, RevTree mergeTree, boolean ignoreConflicts)
			throws IOException {

		builder = dircache.builder();
		DirCacheBuildIterator buildIt = new DirCacheBuildIterator(builder);

		tw = new NameConflictTreeWalk(db, reader);
		tw.addTree(baseTree);
		tw.addTree(headTree);
		tw.addTree(mergeTree);
		int dciPos = tw.addTree(buildIt);
		if (workingTreeIterator != null) {
			tw.addTree(workingTreeIterator);
			workingTreeIterator.setDirCacheIterator(tw, dciPos);
		} else {
			tw.setFilter(TreeFilter.ANY_DIFF);
		}

		if (!mergeTreeWalk(tw, ignoreConflicts)) {
			return false;
		}

		if (!inCore) {
			// No problem found. The only thing left to be done is to
			// checkout all files from "theirs" which have been selected to
			// go into the new index.
			checkout();

			// All content-merges are successfully done. If we can now write the
			// new index we are on quite safe ground. Even if the checkout of
			// files coming from "theirs" fails the user can work around such
			// failures by checking out the index again.
			if (!builder.commit()) {
				cleanUp();
				throw new IndexWriteException();
			}
			builder = null;

		} else {
			builder.finish();
			builder = null;
		}

		if (getUnmergedPaths().isEmpty() && !failed()) {
			resultTree = dircache.writeTree(getObjectInserter());
			return true;
		} else {
			resultTree = null;
			return false;
		}
	}

	
Process the given TreeWalk's entries.

Params:
Throws:
Returns:Whether the trees merged cleanly.
Since:3.5
/**
	 * Process the given TreeWalk's entries.
	 *
	 * @param treeWalk
	 *            The walk to iterate over.
	 * @param ignoreConflicts
	 *            see
	 *            {@link org.eclipse.jgit.merge.ResolveMerger#mergeTrees(AbstractTreeIterator, RevTree, RevTree, boolean)}
	 * @return Whether the trees merged cleanly.
	 * @throws java.io.IOException
	 * @since 3.5
	 */
	protected boolean mergeTreeWalk(TreeWalk treeWalk, boolean ignoreConflicts)
			throws IOException {
		boolean hasWorkingTreeIterator = tw.getTreeCount() > T_FILE;
		boolean hasAttributeNodeProvider = treeWalk
				.getAttributesNodeProvider() != null;
		while (treeWalk.next()) {
			if (!processEntry(
					treeWalk.getTree(T_BASE, CanonicalTreeParser.class),
					treeWalk.getTree(T_OURS, CanonicalTreeParser.class),
					treeWalk.getTree(T_THEIRS, CanonicalTreeParser.class),
					treeWalk.getTree(T_INDEX, DirCacheBuildIterator.class),
					hasWorkingTreeIterator ? treeWalk.getTree(T_FILE,
							WorkingTreeIterator.class) : null,
					ignoreConflicts, hasAttributeNodeProvider
							? treeWalk.getAttributes()
							: NO_ATTRIBUTES)) {
				cleanUp();
				return false;
			}
			if (treeWalk.isSubtree() && enterSubtree)
				treeWalk.enterSubtree();
		}
		return true;
	}
}