Implement hasChildren() to avoid diff calculation in UI thread

Fetch/Push result table content provider will now always report "true"
in hasChildren() if the requested object is a RepositoryCommit.

This is needed for tree viewer to paint "arrows" for expandable nodes
without calculation of the commit content - this calculation on huge
repositories can block UI thread forever.

Bug: 458839
Change-Id: I78ec6b62f36b46932a38fbcbea1fda2c61af9089
Signed-off-by: Andrey Loskutov <loskutov@gmx.de>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

2 files changed, 23 insertions, 2 deletions

diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/fetch/FetchResultTable.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/fetch/FetchResultTable.java
index a7893e363a..5ab4a09d49 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/fetch/FetchResultTable.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/fetch/FetchResultTable.java
@@ -353,11 +353,21 @@ class FetchResultTable {
 			}
 
 			public Object[] getChildren(Object element) {
-				if (element instanceof RepositoryCommit)
+				if (element instanceof RepositoryCommit) {
 					return ((RepositoryCommit) element).getDiffs();
+				}
 				return super.getChildren(element);
 			}
 
+			@Override
+			public boolean hasChildren(Object element) {
+				if (element instanceof RepositoryCommit) {
+					// always return true for commits to avoid commit diff
+					// calculation in UI thread, see bug 458839
+					return true;
+				}
+				return super.hasChildren(element);
+			}
 		});
 
 		new OpenAndLinkWithEditorHelper(treeViewer) {
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/push/RefUpdateContentProvider.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/push/RefUpdateContentProvider.java
index d9b6d38fd9..16cd9972b5 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/push/RefUpdateContentProvider.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/push/RefUpdateContentProvider.java
@@ -29,8 +29,19 @@ class RefUpdateContentProvider extends WorkbenchContentProvider {
 	}
 
 	public Object[] getChildren(Object element) {
-		if (element instanceof RepositoryCommit)
+		if (element instanceof RepositoryCommit) {
 			return ((RepositoryCommit) element).getDiffs();
+		}
 		return super.getChildren(element);
 	}
+
+	@Override
+	public boolean hasChildren(Object element) {
+		if (element instanceof RepositoryCommit) {
+			// always return true for commits to avoid commit diff calculation
+			// in UI thread, see bug 458839
+			return true;
+		}
+		return super.hasChildren(element);
+	}
 }