Enable cherry-pick conflict resolution

When a cherry-pick fails due to conflicts, the user has to resolve the
situation. With this change, the repository is set to the "Conflicts"
state and the merge tool is enabled.

Also, the original commit message and author is preset in the commit
dialog. The message includes a "Conflicts" section as in C git.

This depends on JGit change I947967fdc2f1d55016c95106b104c2afcc9797a1.

Bug: 339092
Change-Id: I5c5b98c98cf8deefa27de6cb94afa189a2cba218
Signed-off-by: Robin Stocker <robin@nibor.org>

9 files changed, 65 insertions, 4 deletions

diff --git a/org.eclipse.egit.core/src/org/eclipse/egit/core/CoreText.java b/org.eclipse.egit.core/src/org/eclipse/egit/core/CoreText.java
index 8a6a43ffb2..d520e96f1c 100644
--- a/org.eclipse.egit.core/src/org/eclipse/egit/core/CoreText.java
+++ b/org.eclipse.egit.core/src/org/eclipse/egit/core/CoreText.java
@@ -159,6 +159,9 @@ public class CoreText extends NLS {
 	public static String ResetOperation_resetMergeFailed;
 
 	/** */
+	public static String ResetOperation_resetCherryPickFailed;
+
+	/** */
 	public static String ResetOperation_updatingFailed;
 
 	/** */
diff --git a/org.eclipse.egit.core/src/org/eclipse/egit/core/coretext.properties b/org.eclipse.egit.core/src/org/eclipse/egit/core/coretext.properties
index fab38065ca..5a541be2a2 100644
--- a/org.eclipse.egit.core/src/org/eclipse/egit/core/coretext.properties
+++ b/org.eclipse.egit.core/src/org/eclipse/egit/core/coretext.properties
@@ -57,6 +57,7 @@ ResetOperation_mappingTreeForCommit=mapping tree for commit
 ResetOperation_performingReset=Performing {0} reset to {1}
 ResetOperation_readingIndex=Reading index
 ResetOperation_resetMergeFailed=Resetting merge mode failed
+ResetOperation_resetCherryPickFailed=Resetting cherry pick mode failed
 ResetOperation_updatingFailed=Updating {0} failed
 
 MergeOperation_InternalError=An internal error occurred
diff --git a/org.eclipse.egit.core/src/org/eclipse/egit/core/op/ResetOperation.java b/org.eclipse.egit.core/src/org/eclipse/egit/core/op/ResetOperation.java
index 5fe4832d44..43141a3f90 100644
--- a/org.eclipse.egit.core/src/org/eclipse/egit/core/op/ResetOperation.java
+++ b/org.eclipse.egit.core/src/org/eclipse/egit/core/op/ResetOperation.java
@@ -124,6 +124,8 @@ public class ResetOperation implements IEGitOperation {
 				|| repository.getRepositoryState().equals(
 						RepositoryState.MERGING_RESOLVED))
 			merging = true;
+		final boolean cherryPicking = repository.getRepositoryState().equals(RepositoryState.CHERRY_PICKING)
+			|| repository.getRepositoryState().equals(RepositoryState.CHERRY_PICKING_RESOLVED);
 
 		mapObjects();
 		monitor.worked(1);
@@ -137,6 +139,8 @@ public class ResetOperation implements IEGitOperation {
 			monitor.worked(1);
 			if (merging)
 				resetMerge();
+			if (cherryPicking)
+				resetCherryPick();
 			monitor.worked(1);
 			// only refresh if working tree changes
 			ProjectUtil.refreshValidProjects(validProjects, new SubProgressMonitor(
@@ -150,6 +154,8 @@ public class ResetOperation implements IEGitOperation {
 			monitor.worked(2);
 			if (merging)
 				resetMerge();
+			if (cherryPicking)
+				resetCherryPick();
 			monitor.worked(1);
 			break;
 
@@ -169,6 +175,15 @@ public class ResetOperation implements IEGitOperation {
 		}
 	}
 
+	private void resetCherryPick() throws CoreException {
+		try {
+			repository.writeCherryPickHead(null);
+			repository.writeMergeCommitMsg(null);
+		} catch (IOException e) {
+			throw new TeamException(CoreText.ResetOperation_resetCherryPickFailed, e);
+		}
+	}
+
 	private void mapObjects() throws TeamException {
 		final ObjectId commitId;
 		try {
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/UIText.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/UIText.java
index ca439a543e..09ce1387a6 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/UIText.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/UIText.java
@@ -655,6 +655,12 @@ public class UIText extends NLS {
 	public static String CherryPickHandler_NoCherryPickPerformedTitle;
 
 	/** */
+	public static String CherryPickHandler_CherryPickConflictsMessage;
+
+	/** */
+	public static String CherryPickHandler_CherryPickConflictsTitle;
+
+	/** */
 	public static String CherryPickOperation_Failed;
 
 	/** */
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions/MergeToolActionHandler.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions/MergeToolActionHandler.java
index a5f8ee86d5..f29be99f9e 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions/MergeToolActionHandler.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions/MergeToolActionHandler.java
@@ -53,6 +53,8 @@ public class MergeToolActionHandler extends RepositoryActionHandler {
 		switch (repos[0].getRepositoryState()) {
 		case MERGING:
 			// fall through
+		case CHERRY_PICKING:
+			// fall through
 		case REBASING:
 			// fall through
 		case REBASING_INTERACTIVE:
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/commit/CommitUI.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/commit/CommitUI.java
index 20d3081e49..72b780da6f 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/commit/CommitUI.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/commit/CommitUI.java
@@ -153,6 +153,7 @@ public class CommitUI  {
 		Repository mergeRepository = null;
 		amendAllowed = repos.length == 1;
 		boolean isMergedResolved = false;
+		boolean isCherryPickResolved = false;
 		for (Repository repo : repos) {
 			repository = repo;
 			RepositoryState state = repo.getRepositoryState();
@@ -167,6 +168,10 @@ public class CommitUI  {
 				isMergedResolved = true;
 				mergeRepository = repo;
 			}
+			else if (state.equals(RepositoryState.CHERRY_PICKING_RESOLVED)) {
+				isCherryPickResolved = true;
+				mergeRepository = repo;
+			}
 		}
 		if (amendAllowed)
 			loadPreviousCommit(repos[0]);
@@ -206,7 +211,7 @@ public class CommitUI  {
 		commitDialog.setPreselectedFiles(getSelectedFiles());
 		commitDialog.setAuthor(author);
 		commitDialog.setCommitter(committer);
-		commitDialog.setAllowToChangeSelection(!isMergedResolved);
+		commitDialog.setAllowToChangeSelection(!isMergedResolved && !isCherryPickResolved);
 
 		if (previousCommit != null) {
 			commitDialog.setPreviousCommitMessage(previousCommit.getFullMessage());
@@ -214,10 +219,14 @@ public class CommitUI  {
 			commitDialog.setPreviousAuthor(previousAuthor.getName()
 					+ " <" + previousAuthor.getEmailAddress() + ">"); //$NON-NLS-1$ //$NON-NLS-2$
 		}
-		if (isMergedResolved) {
+		if (isMergedResolved || isCherryPickResolved) {
 			commitDialog.setCommitMessage(getMergeResolveMessage(mergeRepository));
 		}
 
+		if (isCherryPickResolved) {
+			commitDialog.setAuthor(getCherryPickOriginalAuthor(mergeRepository));
+		}
+
 		if (commitDialog.open() != IDialogConstants.OK_ID)
 			return;
 
@@ -456,6 +465,18 @@ public class CommitUI  {
 		}
 	}
 
+	private String getCherryPickOriginalAuthor(Repository mergeRepository) {
+		try {
+			ObjectId cherryPickHead = mergeRepository.readCherryPickHead();
+			PersonIdent author = new RevWalk(mergeRepository).parseCommit(cherryPickHead).getAuthorIdent();
+			return author.getName() + " <" + author.getEmailAddress() + ">";  //$NON-NLS-1$//$NON-NLS-2$
+		} catch (IOException e) {
+			Activator.handleError(UIText.CommitAction_errorRetrievingCommit, e,
+					true);
+			throw new IllegalStateException(e);
+		}
+	}
+
 	private String newLine() {
 		return System.getProperty("line.separator"); //$NON-NLS-1$
 	}
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/history/command/CherryPickHandler.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/history/command/CherryPickHandler.java
index 5d8d41e706..ef9b3299ba 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/history/command/CherryPickHandler.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/history/command/CherryPickHandler.java
@@ -18,8 +18,10 @@ import org.eclipse.egit.ui.UIText;
 import org.eclipse.jface.dialogs.MessageDialog;
 import org.eclipse.jgit.api.CherryPickResult;
 import org.eclipse.jgit.api.Git;
+import org.eclipse.jgit.api.CherryPickResult.CherryPickStatus;
 import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.revwalk.RevCommit;
+import org.eclipse.swt.widgets.Shell;
 
 /**
  * Executes the CherryPick
@@ -32,18 +34,25 @@ public class CherryPickHandler extends AbstractHistoryCommandHandler {
 
 		CherryPickResult cherryPickResult;
 		Git git = new Git(repo);
+		Shell parent = getPart(event).getSite().getShell();
 		try {
 			cherryPickResult = git.cherryPick().include(commit.getId()).call();
 			newHead = cherryPickResult.getNewHead();
 			if (newHead != null && cherryPickResult.getCherryPickedRefs().isEmpty())
-				MessageDialog.openWarning(getPart(event).getSite().getShell(),
+				MessageDialog.openWarning(parent,
 						UIText.CherryPickHandler_NoCherryPickPerformedTitle,
 						UIText.CherryPickHandler_NoCherryPickPerformedMessage);
 		} catch (Exception e) {
 			throw new ExecutionException(UIText.CherryPickOperation_InternalError, e);
 		}
 		if (newHead == null)
-			throw new ExecutionException(UIText.CherryPickOperation_Failed);
+			if (cherryPickResult.getStatus() == CherryPickStatus.CONFLICTING)
+				MessageDialog.openWarning(parent,
+						UIText.CherryPickHandler_CherryPickConflictsTitle,
+						UIText.CherryPickHandler_CherryPickConflictsMessage);
+			else
+				throw new ExecutionException(UIText.CherryPickOperation_Failed);
+
 		return null;
 	}
 }
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/merge/GitMergeEditorInput.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/merge/GitMergeEditorInput.java
index c4e283c4c6..222ac16ce5 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/merge/GitMergeEditorInput.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/merge/GitMergeEditorInput.java
@@ -135,6 +135,8 @@ public class GitMergeEditorInput extends CompareEditorInput {
 				String target;
 				if (repo.getRepositoryState().equals(RepositoryState.MERGING))
 					target = Constants.MERGE_HEAD;
+				else if (repo.getRepositoryState().equals(RepositoryState.CHERRY_PICKING))
+					target = Constants.CHERRY_PICK_HEAD;
 				else if (repo.getRepositoryState().equals(
 						RepositoryState.REBASING_INTERACTIVE))
 					target = readFile(repo.getDirectory(),
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/uitext.properties b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/uitext.properties
index 2657c88e09..0e452dbea0 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/uitext.properties
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/uitext.properties
@@ -162,6 +162,8 @@ CheckoutHandler_SelectBranchMessage=There is more than one branch for this commi
 CheckoutHandler_SelectBranchTitle=Select a branch for checkout
 CherryPickHandler_NoCherryPickPerformedMessage=The change has already been included
 CherryPickHandler_NoCherryPickPerformedTitle=No cherry pick performed
+CherryPickHandler_CherryPickConflictsMessage=Cherry pick could not be completed automatically because of conflicts. Please resolve and commit.
+CherryPickHandler_CherryPickConflictsTitle=Cherry Pick Conflicts
 CherryPickOperation_Failed=The cherry-pick failed
 CherryPickOperation_InternalError=An internal error occurred
 CompareTargetSelectionDialog_CompareButton=&Compare