Add semantic highlighting to the Java compare/merge viewer #2929

Author: Philipp0205

org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/compare/JavaMergeViewer.java

@@ -622,6 +622,10 @@ protected void doSetInput(IEditorInput input) throws CoreException {
 			super.doSetInput(input);
 			// the editor input has been explicitly set
 			fInputSet = true;
+
+			if (getInputJavaElement() != null) {
+				installSemanticHighlighting();
+			}
 		}
 		// called by org.eclipse.ui.texteditor.TextEditorAction.canModifyEditor()
 		@Override