[historyView] Track renamed paths and provide to actions

Several History view actions currently fail when the view is
set to follow renames since they derive the path used from
the current repository path and do not take into account
older paths that the resource was known as.

This commit creates a simple RenameTracker class that tracks
which commits introduced renames allowing the GitHistoryPage
to provide the previous paths for a specific commit given the
initial path.

At the moment, rename tracking only works when "Show all changes of
selected resource and its children" is checked, because JGit currently
does not allow combining a FollowFilter with e.g. a PathFilter.

The commit also makes the commit viewer's "Compare with Previous
Version" honour renames.

Caveat: This change unfortunately undoes some of the work in
I4ae8abfc4dbe7ed772749afa80743278247585ee and my manual test coverage is
pretty low (IFile and IResource only)

Bug: 374722
Change-Id: Ieddbfb06418b146e5066a7ef2eda51ab4af858e2
AlsoBy: Kevin Sawicki <kevin@github.com>
AlsoBy: Robin Rosenberg <robin.rosenberg@dewire.com>
Signed-off-by: Carsten Pfeiffer <carsten.pfeiffer@gebit.de>

1 files changed, 24 insertions, 1 deletions

diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/history/GitHistoryPage.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/history/GitHistoryPage.java
index 636cba1859..8a27d32835 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/history/GitHistoryPage.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/history/GitHistoryPage.java
@@ -696,6 +696,8 @@ public class GitHistoryPage extends HistoryPage implements RefsChangedListener,
 
 	private Runnable refschangedRunnable;
 
+	private final RenameTracker renameTracker = new RenameTracker();
+
 	/**
 	 * Determine if the input can be shown in this viewer.
 	 *
@@ -1051,6 +1053,7 @@ public class GitHistoryPage extends HistoryPage implements RefsChangedListener,
 				if (i instanceof IWorkbenchAction)
 					((IWorkbenchAction) i).dispose();
 		}
+		renameTracker.reset(null);
 		super.dispose();
 	}
 
@@ -1825,6 +1828,8 @@ public class GitHistoryPage extends HistoryPage implements RefsChangedListener,
 			fileViewerInterestingPaths = new HashSet<String>(selectedPaths);
 			TreeFilter followFilter = createFollowFilterFor(selectedPaths);
 			walk.setTreeFilter(followFilter);
+			walk.setRevFilter(renameTracker.getFilter());
+
 		} else if (paths.size() > 0) {
 			pathFilters = paths;
 			List<String> stringPaths = new ArrayList<String>(paths.size());
@@ -1858,9 +1863,15 @@ public class GitHistoryPage extends HistoryPage implements RefsChangedListener,
 		for (String path : paths)
 			followFilters.add(createFollowFilter(path, diffConfig));
 
-		if (followFilters.size() == 1)
+		if (followFilters.size() == 1) {
+			FollowFilter followFilter = (FollowFilter) followFilters.get(0);
+			renameTracker.reset(followFilter.getPath());
 			return followFilters.get(0);
+		}
 
+		// TODO: this scenario is not supported by JGit: RewriteTreeFilter
+		// can not handle composite TreeFilters and expects a plain
+		// FollowFilter for rename detection.
 		return OrTreeFilter.create(followFilters);
 	}
 
@@ -1869,6 +1880,7 @@ public class GitHistoryPage extends HistoryPage implements RefsChangedListener,
 		followFilter.setRenameCallback(new RenameCallback() {
 			@Override
 			public void renamed(DiffEntry entry) {
+				renameTracker.getCallback().renamed(entry);
 				if (fileViewerInterestingPaths != null) {
 					fileViewerInterestingPaths.add(entry.getOldPath());
 					fileViewerInterestingPaths.add(entry.getNewPath());
@@ -2039,4 +2051,15 @@ public class GitHistoryPage extends HistoryPage implements RefsChangedListener,
 	public String[] getShowInTargetIds() {
 		return new String[] { IHistoryView.VIEW_ID };
 	}
+
+	/**
+	 * Get renamed path in given commit with initial starting path
+	 *
+	 * @param path
+	 * @param commit
+	 * @return actual path in commit
+	 */
+	public String getRenamedPath(String path, ObjectId commit) {
+		return renameTracker.getPath(commit, path);
+	}
 }