From d056a543846ccf9b8cd0f59cc2f5920427fc4559 Mon Sep 17 00:00:00 2001
From: Ned Twigg <ned.twigg@diffplug.com>
Date: Tue, 21 Aug 2018 14:44:28 -0700
Subject: [PATCH] CheckoutCommand: force flag now allows overwrite

Before this commit, a force checkout would fail if there
were any conflicting files. After this commit, a force
checkout will overwrite the conflicting files, as expected.

Making this work required fixing a bug in DirCacheCheckout.
Before this commit, when DirCacheCheckout had
failOnConflict=false, it would delete all conflicting files
from the working copy and just leave them missing. After
this commit, DirCacheCheckout overwrites conflicting files
with the merge tree.

This change in DirCacheCheckout causes "reset --hard" and
"revert --abort" to behave as expected (previously they
would simply delete conflicting files, now they will be
overwritten from the merge tree).

Change-Id: If7e328ee792ef6511ab7d9c26d8d77c39210ec9f
Signed-off-by: Ned Twigg <ned.twigg@diffplug.com>
---
 .../eclipse/jgit/api/CheckoutCommandTest.java |  4 ++-
 .../org/eclipse/jgit/api/CheckoutCommand.java |  2 +-
 .../jgit/dircache/DirCacheCheckout.java       | 29 ++++++++++++++++++-
 3 files changed, 32 insertions(+), 3 deletions(-)

diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/CheckoutCommandTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/CheckoutCommandTest.java
index 71df59e1ff..498005deda 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/CheckoutCommandTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/CheckoutCommandTest.java
@@ -154,7 +154,7 @@ public class CheckoutCommandTest extends RepositoryTestCase {
 	}
 
 	@Test
-	public void testCheckoutWithConflict() {
+	public void testCheckoutWithConflict() throws Exception {
 		CheckoutCommand co = git.checkout();
 		try {
 			writeTrashFile("Test.txt", "Another change");
@@ -165,6 +165,8 @@ public class CheckoutCommandTest extends RepositoryTestCase {
 			assertEquals(Status.CONFLICTS, co.getResult().getStatus());
 			assertTrue(co.getResult().getConflictList().contains("Test.txt"));
 		}
+		git.checkout().setName("master").setForce(true).call();
+		assertThat(read("Test.txt"), is("Hello world"));
 	}
 
 	@Test
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/api/CheckoutCommand.java b/org.eclipse.jgit/src/org/eclipse/jgit/api/CheckoutCommand.java
index 11edb10894..455a2e665f 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/api/CheckoutCommand.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/api/CheckoutCommand.java
@@ -269,7 +269,7 @@ public class CheckoutCommand extends GitCommand<Ref> {
 			try {
 				dco = new DirCacheCheckout(repo, headTree, dc,
 						newCommit.getTree());
-				dco.setFailOnConflict(true);
+				dco.setFailOnConflict(!force);
 				dco.setProgressMonitor(monitor);
 				try {
 					dco.checkout();
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/dircache/DirCacheCheckout.java b/org.eclipse.jgit/src/org/eclipse/jgit/dircache/DirCacheCheckout.java
index ca1e3ab275..db6073f89a 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/dircache/DirCacheCheckout.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/dircache/DirCacheCheckout.java
@@ -522,7 +522,7 @@ public class DirCacheCheckout {
 			builder.finish();
 
 			// init progress reporting
-			int numTotal = removed.size() + updated.size();
+			int numTotal = removed.size() + updated.size() + conflicts.size();
 			monitor.beginTask(JGitText.get().checkingOutFiles, numTotal);
 
 			performingCheckout = true;
@@ -597,6 +597,33 @@ public class DirCacheCheckout {
 				}
 				throw ex;
 			}
+			for (String conflict : conflicts) {
+				// the conflicts are likely to have multiple entries in the
+				// dircache, we only want to check out the one for the "theirs"
+				// tree
+				int entryIdx = dc.findEntry(conflict);
+				if (entryIdx >= 0) {
+					while (entryIdx < dc.getEntryCount()) {
+						DirCacheEntry entry = dc.getEntry(entryIdx);
+						if (!entry.getPathString().equals(conflict)) {
+							break;
+						}
+						if (entry.getStage() == DirCacheEntry.STAGE_3) {
+							checkoutEntry(repo, entry, objectReader, false,
+									null);
+							break;
+						}
+						++entryIdx;
+					}
+				}
+
+				monitor.update(1);
+				if (monitor.isCancelled()) {
+					throw new CanceledException(MessageFormat.format(
+							JGitText.get().operationCanceled,
+							JGitText.get().checkingOutFiles));
+				}
+			}
 			monitor.endTask();
 
 			// commit the index builder - a new index is persisted
-- 
2.39.5