Make tracing 3.4 compatible and plug-in local

Sharing trace classes between plug-ins is bad, as the OSGI tracing
infrastructure will write the ID of plug-in that exposes the trace
class into the trace file. Instead the ID of the plug-in that is
writing the trace should be written. This is achieved by obtaining a
separate Location for each plug-in.

In order to achieve 3.4. compatibility, a temporary trace
implementation using System.out is used.

Bug: 306793

Change-Id: 	I2765961f9c0b886995e74b03404e1f20aadf7b28
Signed-off-by: Mathias Kinzler <mathias.kinzler@sap.com>
Signed-off-by: Robin Rosenberg <robin.rosenberg@dewire.com>

19 files changed, 336 insertions, 55 deletions

diff --git a/org.eclipse.egit.core/.options b/org.eclipse.egit.core/.options
index 36f7a0db3d..efb197e464 100644
--- a/org.eclipse.egit.core/.options
+++ b/org.eclipse.egit.core/.options
@@ -2,5 +2,4 @@
 org.eclipse.egit.core/debug = false
 # General trace location for the EGit Core Plugin
 org.eclipse.egit.core/debug/core = false
-# General trace location for the EGit UI Plugin
-org.eclipse.egit.core/debug/ui = false
+
diff --git a/org.eclipse.egit.core/META-INF/MANIFEST.MF b/org.eclipse.egit.core/META-INF/MANIFEST.MF
index 44a6adaf72..029397b3b3 100644
--- a/org.eclipse.egit.core/META-INF/MANIFEST.MF
+++ b/org.eclipse.egit.core/META-INF/MANIFEST.MF
@@ -12,7 +12,6 @@ Require-Bundle: org.eclipse.core.runtime;bundle-version="[3.4.0,4.0.0)",
  org.eclipse.core.filesystem;bundle-version="[1.2.0,2.0.0)"
 Export-Package: org.eclipse.egit.core;version="0.8.0",
  org.eclipse.egit.core.internal.storage;version="0.8.0";x-friends:="org.eclipse.egit.ui",
- org.eclipse.egit.core.internal.trace;version="0.8.0";x-friends:="org.eclipse.egit.ui",
  org.eclipse.egit.core.internal.util;version="0.8.0";x-friends:="org.eclipse.egit.ui",
  org.eclipse.egit.core.op;version="0.8.0",
  org.eclipse.egit.core.project;version="0.8.0"
diff --git a/org.eclipse.egit.core/src/org/eclipse/egit/core/Activator.java b/org.eclipse.egit.core/src/org/eclipse/egit/core/Activator.java
index 572c14628e..a63dcfc381 100644
--- a/org.eclipse.egit.core/src/org/eclipse/egit/core/Activator.java
+++ b/org.eclipse.egit.core/src/org/eclipse/egit/core/Activator.java
@@ -9,8 +9,6 @@
  *******************************************************************************/
 package org.eclipse.egit.core;
 
-import java.util.Hashtable;
-
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.Plugin;
@@ -18,14 +16,14 @@ import org.eclipse.core.runtime.Status;
 import org.eclipse.egit.core.internal.trace.GitTraceLocation;
 import org.eclipse.egit.core.project.GitProjectData;
 import org.eclipse.osgi.service.debug.DebugOptions;
-import org.eclipse.osgi.service.debug.DebugOptionsListener;
 import org.osgi.framework.BundleContext;
+import org.osgi.util.tracker.ServiceTracker;
 
 /**
  * The plugin class for the org.eclipse.egit.core plugin. This
  * is a singleton class.
  */
-public class Activator extends Plugin implements DebugOptionsListener {
+public class Activator extends Plugin {
 	private static Activator plugin;
 
 	/**
@@ -73,12 +71,17 @@ public class Activator extends Plugin implements DebugOptionsListener {
 	}
 
 	public void start(final BundleContext context) throws Exception {
+
 		super.start(context);
-        // register this as DebugOptions listener
-		Hashtable<String, String> props = new Hashtable<String, String>(4);
-		// we want to get notified about our own DebugOptions
-		props.put(DebugOptions.LISTENER_SYMBOLICNAME, context.getBundle().getSymbolicName());
-		context.registerService(DebugOptionsListener.class.getName(), this, props);
+
+		if (isDebugging()) {
+			ServiceTracker debugTracker = new ServiceTracker(context,
+					DebugOptions.class.getName(), null);
+			debugTracker.open();
+
+			DebugOptions opts = (DebugOptions) debugTracker.getService();
+			GitTraceLocation.initializeFromOptions(opts, true);
+		}
 
 		GitProjectData.reconfigureWindowCache();
 		GitProjectData.attachToWorkspace(true);
@@ -90,7 +93,4 @@ public class Activator extends Plugin implements DebugOptionsListener {
 		plugin = null;
 	}
 
-	public void optionsChanged(DebugOptions options) {
-		GitTraceLocation.initializeFromOptions(options, isDebugging());
-	}
 }
diff --git a/org.eclipse.egit.core/src/org/eclipse/egit/core/internal/trace/DebugTrace.java b/org.eclipse.egit.core/src/org/eclipse/egit/core/internal/trace/DebugTrace.java
new file mode 100644
index 0000000000..a7ecdc5573
--- /dev/null
+++ b/org.eclipse.egit.core/src/org/eclipse/egit/core/internal/trace/DebugTrace.java
@@ -0,0 +1,24 @@
+package org.eclipse.egit.core.internal.trace;
+
+/**
+ * Just a place holder for OSGI Debug Trace support until
+ * we drop 3.4 support in EGit/JGit;
+ *
+ * TODO replace this by OSGI's DebugTrace once we drop 3.4 support
+ */
+public interface DebugTrace {
+
+	/**
+	 * @param location
+	 * @param message
+	 */
+	public void trace(String location, String message);
+
+	/**
+	 * @param location
+	 * @param message
+	 * @param error
+	 */
+	public void trace(String location, String message, Throwable error);
+
+}
diff --git a/org.eclipse.egit.core/src/org/eclipse/egit/core/internal/trace/GitTraceLocation.java b/org.eclipse.egit.core/src/org/eclipse/egit/core/internal/trace/GitTraceLocation.java
index 92f8510f19..382283f44d 100644
--- a/org.eclipse.egit.core/src/org/eclipse/egit/core/internal/trace/GitTraceLocation.java
+++ b/org.eclipse.egit.core/src/org/eclipse/egit/core/internal/trace/GitTraceLocation.java
@@ -10,9 +10,11 @@
  *******************************************************************************/

 package org.eclipse.egit.core.internal.trace;

 

+import org.eclipse.core.runtime.ILog;

+import org.eclipse.core.runtime.IStatus;

+import org.eclipse.core.runtime.Status;

 import org.eclipse.egit.core.Activator;

 import org.eclipse.osgi.service.debug.DebugOptions;

-import org.eclipse.osgi.service.debug.DebugTrace;

 

 /**

  * EGit Trace locations

@@ -20,9 +22,7 @@ import org.eclipse.osgi.service.debug.DebugTrace;
  */

 public enum GitTraceLocation implements ITraceLocation {

 	/** Core */

-	CORE("/debug/core"), //$NON-NLS-1$

-	/** UI */

-	UI("/debug/ui"); //$NON-NLS-1$

+	CORE("/debug/core"); //$NON-NLS-1$

 

 	/**

 	 * Initialize the locations

@@ -30,13 +30,15 @@ public enum GitTraceLocation implements ITraceLocation {
 	 * @param options

 	 * @param pluginIsDebugging

 	 */

-	public static void initializeFromOptions(DebugOptions options, boolean pluginIsDebugging) {

+	public static void initializeFromOptions(DebugOptions options,

+			boolean pluginIsDebugging) {

 

 		// we evaluate the plug-in switch

 		if (pluginIsDebugging) {

-			myTrace = options.newDebugTrace(Activator.getPluginId());

+			myTrace = new DebugTraceImpl();

 			for (GitTraceLocation loc : values()) {

-				boolean active = options.getBooleanOption(loc.getFullPath(), false);

+				boolean active = options.getBooleanOption(loc.getFullPath(),

+						false);

 				loc.setActive(active);

 			}

 		} else {

@@ -49,9 +51,11 @@ public enum GitTraceLocation implements ITraceLocation {
 	}

 

 	private final String location;

+

 	private final String fullPath;

 

 	private boolean active = false;

+

 	private static DebugTrace myTrace;

 

 	private GitTraceLocation(String path) {

@@ -100,4 +104,33 @@ public enum GitTraceLocation implements ITraceLocation {
 		this.active = active;

 	}

 

+	private static final class DebugTraceImpl implements DebugTrace {

+

+		private ILog myLog;

+

+		public void trace(String location, String message) {

+			getLog().log(

+					new Status(IStatus.INFO, Activator.getPluginId(), message));

+

+		}

+

+		public void trace(String location, String message, Throwable error) {

+

+			getLog().log(

+					new Status(IStatus.INFO, Activator.getPluginId(), message));

+			if (error != null)

+				getLog().log(

+						new Status(IStatus.INFO, Activator.getPluginId(), error

+								.getMessage()));

+

+		}

+

+		private ILog getLog() {

+			if (myLog == null) {

+				myLog = Activator.getDefault().getLog();

+			}

+			return myLog;

+		}

+

+	}

 }

diff --git a/org.eclipse.egit.ui/.options b/org.eclipse.egit.ui/.options
new file mode 100644
index 0000000000..f7fc816a2f
--- /dev/null
+++ b/org.eclipse.egit.ui/.options
@@ -0,0 +1,4 @@
+# Main Debug Trace switch
+org.eclipse.egit.ui/debug = false
+# General trace location for the EGit UI Plugin
+org.eclipse.egit.ui/debug/ui = false
diff --git a/org.eclipse.egit.ui/META-INF/MANIFEST.MF b/org.eclipse.egit.ui/META-INF/MANIFEST.MF
index d690eb61b4..ab1bb68fce 100644
--- a/org.eclipse.egit.ui/META-INF/MANIFEST.MF
+++ b/org.eclipse.egit.ui/META-INF/MANIFEST.MF
@@ -26,7 +26,6 @@ Bundle-RequiredExecutionEnvironment: J2SE-1.5
 Import-Package: com.jcraft.jsch;version="[0.1.41,0.2.0)",
  org.eclipse.egit.core;version="[0.8.0,0.9.0)",
  org.eclipse.egit.core.internal.storage;version="[0.8.0,0.9.0)",
- org.eclipse.egit.core.internal.trace;version="0.8.0",
  org.eclipse.egit.core.internal.util;version="[0.8.0,0.9.0)",
  org.eclipse.egit.core.op;version="[0.8.0,0.9.0)",
  org.eclipse.egit.core.project;version="[0.8.0,0.9.0)",
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/Activator.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/Activator.java
index eeded22144..d06b33d23c 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/Activator.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/Activator.java
@@ -29,8 +29,8 @@ import org.eclipse.core.runtime.Status;
 import org.eclipse.core.runtime.SubProgressMonitor;
 import org.eclipse.core.runtime.jobs.ISchedulingRule;
 import org.eclipse.core.runtime.jobs.Job;
-import org.eclipse.egit.core.internal.trace.GitTraceLocation;
 import org.eclipse.egit.core.project.RepositoryMapping;
+import org.eclipse.egit.ui.internal.trace.GitTraceLocation;
 import org.eclipse.jface.util.IPropertyChangeListener;
 import org.eclipse.jface.util.PropertyChangeEvent;
 import org.eclipse.jgit.lib.IndexChangedEvent;
@@ -39,12 +39,14 @@ import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.lib.RepositoryListener;
 import org.eclipse.jgit.transport.SshSessionFactory;
 import org.eclipse.jsch.core.IJSchService;
+import org.eclipse.osgi.service.debug.DebugOptions;
 import org.eclipse.swt.graphics.Font;
 import org.eclipse.swt.widgets.Display;
 import org.eclipse.ui.plugin.AbstractUIPlugin;
 import org.eclipse.ui.themes.ITheme;
 import org.osgi.framework.BundleContext;
 import org.osgi.framework.ServiceReference;
+import org.osgi.util.tracker.ServiceTracker;
 
 /**
  * This is a plugin singleton mostly controlling logging.
@@ -167,6 +169,16 @@ public class Activator extends AbstractUIPlugin {
 
 	public void start(final BundleContext context) throws Exception {
 		super.start(context);
+
+		if (isDebugging()) {
+			ServiceTracker debugTracker = new ServiceTracker(context,
+					DebugOptions.class.getName(), null);
+			debugTracker.open();
+
+			DebugOptions opts = (DebugOptions) debugTracker.getService();
+			GitTraceLocation.initializeFromOptions(opts, true);
+		}
+
 		setupSSH(context);
 		setupProxy(context);
 		setupRepoChangeScanner();
@@ -402,4 +414,5 @@ public class Activator extends AbstractUIPlugin {
 		super.stop(context);
 		plugin = null;
 	}
+
 }
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/GitResourceNode.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/GitResourceNode.java
index 1060c5372f..90a4ed4a3d 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/GitResourceNode.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/GitResourceNode.java
@@ -19,7 +19,7 @@ import org.eclipse.compare.CompareUI;
 import org.eclipse.compare.ITypedElement;
 import org.eclipse.compare.structuremergeviewer.IStructureComparator;
 import org.eclipse.core.runtime.CoreException;
-import org.eclipse.egit.core.internal.trace.GitTraceLocation;
+import org.eclipse.egit.ui.internal.trace.GitTraceLocation;
 import org.eclipse.swt.graphics.Image;
 import org.eclipse.jgit.lib.FileTreeEntry;
 import org.eclipse.jgit.lib.ObjectId;
@@ -56,8 +56,8 @@ public class GitResourceNode extends BufferedContent implements IStructureCompar
 				}
 			} catch (IOException e) {
 				// TODO: eclipse error handling
-				if (GitTraceLocation.CORE.isActive())
-					GitTraceLocation.getTrace().trace(GitTraceLocation.CORE.getLocation(), e.getMessage(), e);
+				if (GitTraceLocation.UI.isActive())
+					GitTraceLocation.getTrace().trace(GitTraceLocation.UI.getLocation(), e.getMessage(), e);
 				children = new GitResourceNode[0];
 			}
 		}
@@ -77,8 +77,8 @@ public class GitResourceNode extends BufferedContent implements IStructureCompar
 				return new ByteArrayInputStream(bytes);
 			} catch (IOException e) {
 				// TODO: eclipse error handling
-				if (GitTraceLocation.CORE.isActive())
-					GitTraceLocation.getTrace().trace(GitTraceLocation.CORE.getLocation(), e.getMessage(), e);
+				if (GitTraceLocation.UI.isActive())
+					GitTraceLocation.getTrace().trace(GitTraceLocation.UI.getLocation(), e.getMessage(), e);
 				return null;
 			}
 		}
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions/BranchAction.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions/BranchAction.java
index d954efe28a..8c50543b74 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions/BranchAction.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions/BranchAction.java
@@ -14,11 +14,11 @@ import java.lang.reflect.InvocationTargetException;
 
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IProgressMonitor;
-import org.eclipse.egit.core.internal.trace.GitTraceLocation;
 import org.eclipse.egit.core.op.BranchOperation;
 import org.eclipse.egit.ui.UIText;
 import org.eclipse.egit.ui.internal.decorators.GitLightweightDecorator;
 import org.eclipse.egit.ui.internal.dialogs.BranchSelectionDialog;
+import org.eclipse.egit.ui.internal.trace.GitTraceLocation;
 import org.eclipse.jface.action.IAction;
 import org.eclipse.jface.dialogs.IDialogConstants;
 import org.eclipse.jface.dialogs.MessageDialog;
@@ -63,8 +63,8 @@ public class BranchAction extends RepositoryAction {
 						new BranchOperation(repository, refName).run(monitor);
 						GitLightweightDecorator.refresh();
 					} catch (final CoreException e) {
-						if (GitTraceLocation.CORE.isActive())
-							GitTraceLocation.getTrace().trace(GitTraceLocation.CORE.getLocation(), e.getMessage(), e);
+						if (GitTraceLocation.UI.isActive())
+							GitTraceLocation.getTrace().trace(GitTraceLocation.UI.getLocation(), e.getMessage(), e);
 						Display.getDefault().asyncExec(new Runnable() {
 							public void run() {
 								handle(
@@ -77,11 +77,11 @@ public class BranchAction extends RepositoryAction {
 				}
 			});
 		} catch (InvocationTargetException e) {
-			if (GitTraceLocation.CORE.isActive())
-				GitTraceLocation.getTrace().trace(GitTraceLocation.CORE.getLocation(), e.getMessage(), e);
+			if (GitTraceLocation.UI.isActive())
+				GitTraceLocation.getTrace().trace(GitTraceLocation.UI.getLocation(), e.getMessage(), e);
 		} catch (InterruptedException e) {
-			if (GitTraceLocation.CORE.isActive())
-				GitTraceLocation.getTrace().trace(GitTraceLocation.CORE.getLocation(), e.getMessage(), e);
+			if (GitTraceLocation.UI.isActive())
+				GitTraceLocation.getTrace().trace(GitTraceLocation.UI.getLocation(), e.getMessage(), e);
 		}
 	}
 
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions/CommitAction.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions/CommitAction.java
index d190103a58..d1cad20f53 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions/CommitAction.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions/CommitAction.java
@@ -25,11 +25,11 @@ import java.util.TimeZone;
 import org.eclipse.core.resources.IFile;
 import org.eclipse.core.resources.IProject;
 import org.eclipse.core.resources.IResource;
-import org.eclipse.egit.core.internal.trace.GitTraceLocation;
 import org.eclipse.egit.core.project.GitProjectData;
 import org.eclipse.egit.core.project.RepositoryMapping;
 import org.eclipse.egit.ui.UIText;
 import org.eclipse.egit.ui.internal.dialogs.CommitDialog;
+import org.eclipse.egit.ui.internal.trace.GitTraceLocation;
 import org.eclipse.jface.action.IAction;
 import org.eclipse.jface.dialogs.IDialogConstants;
 import org.eclipse.jface.dialogs.MessageDialog;
@@ -410,8 +410,8 @@ public class CommitAction extends RepositoryAction {
 								"Couldn't find " + filename); //$NON-NLS-1$
 				}
 			} catch (Exception e) {
-				if (GitTraceLocation.CORE.isActive())
-					GitTraceLocation.getTrace().trace(GitTraceLocation.CORE.getLocation(), e.getMessage(), e);
+				if (GitTraceLocation.UI.isActive())
+					GitTraceLocation.getTrace().trace(GitTraceLocation.UI.getLocation(), e.getMessage(), e);
 				continue;
 			} // if it's outside the workspace, bad things happen
 		}
@@ -431,8 +431,8 @@ public class CommitAction extends RepositoryAction {
 				return true;
 			}
 		} catch (Exception e) {
-			if (GitTraceLocation.CORE.isActive())
-				GitTraceLocation.getTrace().trace(GitTraceLocation.CORE.getLocation(), e.getMessage(), e);
+			if (GitTraceLocation.UI.isActive())
+				GitTraceLocation.getTrace().trace(GitTraceLocation.UI.getLocation(), e.getMessage(), e);
 		}
 		return false;
 	}
@@ -447,11 +447,11 @@ public class CommitAction extends RepositoryAction {
 				return entry.isModified(map.getWorkDir());
 			return false;
 		} catch (UnsupportedEncodingException e) {
-			if (GitTraceLocation.CORE.isActive())
-				GitTraceLocation.getTrace().trace(GitTraceLocation.CORE.getLocation(), e.getMessage(), e);
+			if (GitTraceLocation.UI.isActive())
+				GitTraceLocation.getTrace().trace(GitTraceLocation.UI.getLocation(), e.getMessage(), e);
 		} catch (IOException e) {
-			if (GitTraceLocation.CORE.isActive())
-				GitTraceLocation.getTrace().trace(GitTraceLocation.CORE.getLocation(), e.getMessage(), e);
+			if (GitTraceLocation.UI.isActive())
+				GitTraceLocation.getTrace().trace(GitTraceLocation.UI.getLocation(), e.getMessage(), e);
 		}
 		return false;
 	}
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions/ResetAction.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions/ResetAction.java
index c5c67e64af..576816c626 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions/ResetAction.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions/ResetAction.java
@@ -14,12 +14,12 @@ import java.lang.reflect.InvocationTargetException;
 
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IProgressMonitor;
-import org.eclipse.egit.core.internal.trace.GitTraceLocation;
 import org.eclipse.egit.core.op.ResetOperation;
 import org.eclipse.egit.core.op.ResetOperation.ResetType;
 import org.eclipse.egit.ui.UIText;
 import org.eclipse.egit.ui.internal.decorators.GitLightweightDecorator;
 import org.eclipse.egit.ui.internal.dialogs.BranchSelectionDialog;
+import org.eclipse.egit.ui.internal.trace.GitTraceLocation;
 import org.eclipse.jface.action.IAction;
 import org.eclipse.jface.dialogs.IDialogConstants;
 import org.eclipse.jface.dialogs.MessageDialog;
@@ -60,8 +60,8 @@ public class ResetAction extends RepositoryAction {
 							new ResetOperation(repository, refName, type).run(monitor);
 							GitLightweightDecorator.refresh();
 						} catch (CoreException e) {
-							if (GitTraceLocation.CORE.isActive())
-								GitTraceLocation.getTrace().trace(GitTraceLocation.CORE.getLocation(), e.getMessage(), e);
+							if (GitTraceLocation.UI.isActive())
+								GitTraceLocation.getTrace().trace(GitTraceLocation.UI.getLocation(), e.getMessage(), e);
 							throw new InvocationTargetException(e);
 						}
 					}
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/decorators/GitDocument.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/decorators/GitDocument.java
index 14f572fd12..9b5a43ddca 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/decorators/GitDocument.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/decorators/GitDocument.java
@@ -16,12 +16,11 @@ import org.eclipse.core.resources.IEncodedStorage;
 import org.eclipse.core.resources.IResource;
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.egit.core.GitProvider;
-import org.eclipse.egit.core.internal.trace.GitTraceLocation;
 import org.eclipse.egit.core.project.RepositoryMapping;
 import org.eclipse.egit.ui.Activator;
 import org.eclipse.egit.ui.UIText;
+import org.eclipse.egit.ui.internal.trace.GitTraceLocation;
 import org.eclipse.jface.text.Document;
-import org.eclipse.team.core.RepositoryProvider;
 import org.eclipse.jgit.lib.AnyObjectId;
 import org.eclipse.jgit.lib.Commit;
 import org.eclipse.jgit.lib.Constants;
@@ -34,6 +33,7 @@ import org.eclipse.jgit.lib.RepositoryListener;
 import org.eclipse.jgit.lib.Tree;
 import org.eclipse.jgit.lib.TreeEntry;
 import org.eclipse.osgi.util.NLS;
+import org.eclipse.team.core.RepositoryProvider;
 
 class GitDocument extends Document implements RepositoryListener {
 	private final IResource resource;
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/decorators/GitQuickDiffProvider.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/decorators/GitQuickDiffProvider.java
index 8b3f8cd1c9..f694b4dcf8 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/decorators/GitQuickDiffProvider.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/decorators/GitQuickDiffProvider.java
@@ -16,9 +16,9 @@ import java.util.WeakHashMap;
 import org.eclipse.core.resources.IResource;
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IProgressMonitor;
-import org.eclipse.egit.core.internal.trace.GitTraceLocation;
 import org.eclipse.egit.ui.Activator;
 import org.eclipse.egit.ui.UIText;
+import org.eclipse.egit.ui.internal.trace.GitTraceLocation;
 import org.eclipse.jface.text.IDocument;
 import org.eclipse.team.core.RepositoryProvider;
 import org.eclipse.ui.IEditorInput;
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 f34aa657c8..9491ab0865 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
@@ -27,7 +27,6 @@ import org.eclipse.core.runtime.jobs.Job;
 import org.eclipse.core.runtime.jobs.JobChangeAdapter;
 import org.eclipse.egit.core.ResourceList;
 import org.eclipse.egit.core.internal.storage.GitFileRevision;
-import org.eclipse.egit.core.internal.trace.GitTraceLocation;
 import org.eclipse.egit.core.project.RepositoryMapping;
 import org.eclipse.egit.ui.Activator;
 import org.eclipse.egit.ui.UIIcons;
@@ -35,6 +34,7 @@ import org.eclipse.egit.ui.UIPreferences;
 import org.eclipse.egit.ui.UIText;
 import org.eclipse.egit.ui.internal.EditableRevision;
 import org.eclipse.egit.ui.internal.GitCompareFileRevisionEditorInput;
+import org.eclipse.egit.ui.internal.trace.GitTraceLocation;
 import org.eclipse.jface.action.Action;
 import org.eclipse.jface.action.ActionContributionItem;
 import org.eclipse.jface.action.IAction;
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/preferences/GitProjectPropertyPage.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/preferences/GitProjectPropertyPage.java
index 82b8dc206a..446e96b053 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/preferences/GitProjectPropertyPage.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/preferences/GitProjectPropertyPage.java
@@ -12,9 +12,9 @@ import java.io.IOException;
 
 import org.eclipse.core.resources.IProject;
 import org.eclipse.core.runtime.IAdaptable;
-import org.eclipse.egit.core.internal.trace.GitTraceLocation;
 import org.eclipse.egit.core.project.RepositoryMapping;
 import org.eclipse.egit.ui.UIText;
+import org.eclipse.egit.ui.internal.trace.GitTraceLocation;
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.layout.GridData;
 import org.eclipse.swt.layout.GridLayout;
@@ -81,8 +81,8 @@ public class GitProjectPropertyPage extends PropertyPage {
 			try {
 				fillValues(repository);
 			} catch (IOException e) {
-				if (GitTraceLocation.CORE.isActive())
-					GitTraceLocation.getTrace().trace(GitTraceLocation.CORE.getLocation(), e.getMessage(), e);
+				if (GitTraceLocation.UI.isActive())
+					GitTraceLocation.getTrace().trace(GitTraceLocation.UI.getLocation(), e.getMessage(), e);
 			}
 		}
 
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/trace/DebugTrace.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/trace/DebugTrace.java
new file mode 100644
index 0000000000..1bd3d9f036
--- /dev/null
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/trace/DebugTrace.java
@@ -0,0 +1,35 @@
+package org.eclipse.egit.ui.internal.trace;
+
+/**
+ * Just a place holder for OSGI Debug Trace support until
+ * we drop 3.4 support in EGit/JGit;
+ *
+ * TODO replace this by OSGI's DebugTrace once we drop 3.4 support
+ */
+public interface DebugTrace {
+
+	/**
+	 * @param location
+	 * @param message
+	 */
+	public void trace(String location, String message);
+
+	/**
+	 * @param location
+	 * @param message
+	 * @param error
+	 */
+	public void trace(String location, String message, Throwable error);
+
+	/**
+	 * @param location
+	 */
+	public void traceEntry(String location);
+
+	/**
+	 * @param location
+	 * @param message
+	 */
+	public void traceEntry(String location, String message);
+
+}
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/trace/GitTraceLocation.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/trace/GitTraceLocation.java
new file mode 100644
index 0000000000..40682ac675
--- /dev/null
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/trace/GitTraceLocation.java
@@ -0,0 +1,145 @@
+/*******************************************************************************

+ * Copyright (c) 2010 SAP AG.

+ * All rights reserved. This program and the accompanying materials

+ * are made available under the terms of the Eclipse Public License v1.0

+ * which accompanies this distribution, and is available at

+ * http://www.eclipse.org/legal/epl-v10.html

+ *

+ * Contributors:

+ *    Mathias Kinzler (SAP AG) - initial implementation

+ *******************************************************************************/

+package org.eclipse.egit.ui.internal.trace;

+

+import org.eclipse.core.runtime.ILog;

+import org.eclipse.core.runtime.IStatus;

+import org.eclipse.core.runtime.Status;

+import org.eclipse.egit.ui.Activator;

+import org.eclipse.osgi.service.debug.DebugOptions;

+

+/**

+ * EGit Trace locations

+ */

+public enum GitTraceLocation implements ITraceLocation {

+

+	/** UI */

+	UI("/debug/ui"); //$NON-NLS-1$

+

+	/**

+	 * Initialize the locations

+	 *

+	 * @param options

+	 * @param pluginIsDebugging

+	 */

+	public static void initializeFromOptions(DebugOptions options,

+			boolean pluginIsDebugging) {

+

+		// we evaluate the plug-in switch

+		if (pluginIsDebugging) {

+			myTrace = new DebugTraceImpl();

+

+			for (GitTraceLocation loc : values()) {

+				boolean active = options.getBooleanOption(loc.getFullPath(),

+						false);

+				loc.setActive(active);

+			}

+		} else {

+			// if the plug-in switch is off, we don't set the trace instance

+			// to null to avoid problems with possibly running trace calls

+			for (GitTraceLocation loc : values()) {

+				loc.setActive(false);

+			}

+		}

+	}

+

+	private final String location;

+

+	private final String fullPath;

+

+	private boolean active = false;

+

+	private static DebugTrace myTrace;

+

+	private GitTraceLocation(String path) {

+		this.fullPath = Activator.getPluginId() + path;

+		this.location = path;

+	}

+

+	/**

+	 * Convenience method

+	 *

+	 * @return the debug trace (may be null)

+	 *

+	 **/

+	public static DebugTrace getTrace() {

+		return GitTraceLocation.myTrace;

+	}

+

+	/**

+	 * @return <code>true</code> if this location is active

+	 */

+	public boolean isActive() {

+		return this.active;

+	}

+

+	/**

+	 * @return the full path

+	 */

+	public String getFullPath() {

+		return this.fullPath;

+	}

+

+	public String getLocation() {

+		return this.location;

+	}

+

+	/**

+	 * Sets the "active" flag for this location.

+	 * <p>

+	 * Used by the initializer

+	 *

+	 * @param active

+	 *            the "active" flag

+	 */

+	private void setActive(boolean active) {

+		this.active = active;

+	}

+

+	private static final class DebugTraceImpl implements DebugTrace {

+

+		private ILog myLog;

+

+		public void trace(String location, String message) {

+			getLog().log(

+					new Status(IStatus.INFO, Activator.getPluginId(), message));

+

+		}

+

+		public void trace(String location, String message, Throwable error) {

+

+			getLog().log(

+					new Status(IStatus.INFO, Activator.getPluginId(), message));

+			if (error != null)

+				getLog().log(

+						new Status(IStatus.INFO, Activator.getPluginId(), error

+								.getMessage()));

+

+		}

+

+		public void traceEntry(String location) {

+			// not implemented

+		}

+

+		public void traceEntry(String location, String message) {

+			// not implemented

+		}

+

+		private ILog getLog() {

+			if (myLog == null) {

+				myLog = Activator.getDefault().getLog();

+			}

+			return myLog;

+		}

+

+	}

+

+}

diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/trace/ITraceLocation.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/trace/ITraceLocation.java
new file mode 100644
index 0000000000..4301668496
--- /dev/null
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/trace/ITraceLocation.java
@@ -0,0 +1,30 @@
+/*******************************************************************************

+ * Copyright (c) 2010 SAP AG.

+ * All rights reserved. This program and the accompanying materials

+ * are made available under the terms of the Eclipse Public License v1.0

+ * which accompanies this distribution, and is available at

+ * http://www.eclipse.org/legal/epl-v10.html

+ *

+ * Contributors:

+ *    Mathias Kinzler (SAP AG) - initial implementation

+ *******************************************************************************/

+package org.eclipse.egit.ui.internal.trace;

+

+/**

+ * Helper interface for trace location management

+ * <p>

+ * Additional methods could return a description or such...

+ */

+public interface ITraceLocation {

+

+	/**

+	 * @return the location, e.g. "/debug/mainArea/subArea"

+	 */

+	public String getLocation();

+

+	/**

+	 * @return <code>true</code> if the location is active

+	 */

+	public boolean isActive();

+

+}