From dbd7838aba2f54b28d4d5601f994e70cc2ddab2d Mon Sep 17 00:00:00 2001
From: Michael Keppler
Date: Sun, 4 Aug 2019 07:59:49 +0200
Subject: Always check for merge commit when opening file diff

The 2-way file diff is invoked from 3 different places in the code, but
only one of them checked whether the diff was a merge commit. Move that
check into the file diff method itself to have all 3 invocations
checked.

It might be possible that the other 2 invocations cannot be called for
merge commits due to other external logic, but let's be fault tolerant
here by always forbidding this.

Change-Id: Ieaacc0c0ddf0bdbc273891cd557ab55ff5560133
Signed-off-by: Michael Keppler <Michael.Keppler@gmx.de>
---
 .../src/org/eclipse/egit/ui/internal/commit/DiffViewer.java  | 12 +++++++++++-
 .../egit/ui/internal/history/CommitFileDiffViewer.java       | 11 +----------
 2 files changed, 12 insertions(+), 11 deletions(-)

(limited to 'org.eclipse.egit.ui/src/org/eclipse')

diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/commit/DiffViewer.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/commit/DiffViewer.java
index 53adaff7ec..fce1d12926 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/commit/DiffViewer.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/commit/DiffViewer.java
@@ -51,6 +51,7 @@ import org.eclipse.egit.ui.internal.commit.DiffRegionFormatter.FileDiffRegion;
 import org.eclipse.egit.ui.internal.dialogs.HyperlinkSourceViewer;
 import org.eclipse.egit.ui.internal.history.FileDiff;
 import org.eclipse.egit.ui.internal.revision.GitCompareFileRevisionEditorInput;
+import org.eclipse.jface.dialogs.MessageDialog;
 import org.eclipse.jface.preference.IPreferenceStore;
 import org.eclipse.jface.resource.ColorRegistry;
 import org.eclipse.jface.resource.FontRegistry;
@@ -797,10 +798,19 @@ public class DiffViewer extends HyperlinkSourceViewer {
 	 *            the {@link FileDiff} to show
 	 */
 	public static void showTwoWayFileDiff(FileDiff d) {
+		ObjectId[] blobs = d.getBlobs();
+		if (blobs.length > 2) {
+			MessageDialog.openInformation(
+					PlatformUI.getWorkbench().getActiveWorkbenchWindow()
+							.getShell(),
+					UIText.CommitFileDiffViewer_CanNotOpenCompareEditorTitle,
+					UIText.CommitFileDiffViewer_MergeCommitMultiAncestorMessage);
+			return;
+		}
+
 		String np = d.getNewPath();
 		String op = d.getOldPath();
 		RevCommit c = d.getCommit();
-		ObjectId[] blobs = d.getBlobs();
 
 		// extract commits
 		final RevCommit oldCommit;
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/history/CommitFileDiffViewer.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/history/CommitFileDiffViewer.java
index 793304f40d..7b5f8dfc06 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/history/CommitFileDiffViewer.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/history/CommitFileDiffViewer.java
@@ -60,7 +60,6 @@ import org.eclipse.jface.action.Action;
 import org.eclipse.jface.action.IAction;
 import org.eclipse.jface.action.MenuManager;
 import org.eclipse.jface.action.Separator;
-import org.eclipse.jface.dialogs.MessageDialog;
 import org.eclipse.jface.viewers.ArrayContentProvider;
 import org.eclipse.jface.viewers.ColumnViewerToolTipSupport;
 import org.eclipse.jface.viewers.IOpenListener;
@@ -614,15 +613,7 @@ public class CommitFileDiffViewer extends TableViewer {
 	}
 
 	void showTwoWayFileDiff(final FileDiff d) {
-		if (d.getBlobs().length <= 2) {
-			DiffViewer.showTwoWayFileDiff(d);
-		} else {
-			MessageDialog.openInformation(
-					PlatformUI.getWorkbench().getActiveWorkbenchWindow()
-							.getShell(),
-					UIText.CommitFileDiffViewer_CanNotOpenCompareEditorTitle,
-					UIText.CommitFileDiffViewer_MergeCommitMultiAncestorMessage);
-		}
+		DiffViewer.showTwoWayFileDiff(d);
 	}
 
 	void showWorkingDirectoryFileDiff(final FileDiff d) {
-- 
cgit v1.2.3