Partial fix for 176036: The CEditor does not work well with files opened from outside of the workspace

core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/editor/CDocumentProvider.java

@@ -22,6 +22,8 @@ import org.eclipse.core.resources.IResourceRuleFactory;
 import org.eclipse.core.resources.IStorage;
 import org.eclipse.core.resources.ResourcesPlugin;
 import org.eclipse.core.runtime.CoreException;
+import org.eclipse.core.runtime.IAdaptable;
+import org.eclipse.core.runtime.IPath;
 import org.eclipse.core.runtime.IProgressMonitor;
 import org.eclipse.core.runtime.jobs.ISchedulingRule;
 import org.eclipse.jface.preference.IPreferenceStore;
@@ -40,9 +42,11 @@ import org.eclipse.jface.text.source.IAnnotationModelListener;
 import org.eclipse.jface.text.source.IAnnotationModelListenerExtension;
 import org.eclipse.jface.util.IPropertyChangeListener;
 import org.eclipse.jface.util.PropertyChangeEvent;
+import org.eclipse.ui.IEditorInput;
 import org.eclipse.ui.IFileEditorInput;
 import org.eclipse.ui.IStorageEditorInput;
 import org.eclipse.ui.editors.text.ForwardingDocumentProvider;
+import org.eclipse.ui.editors.text.ILocationProvider;
 import org.eclipse.ui.editors.text.TextFileDocumentProvider;
 import org.eclipse.ui.texteditor.IDocumentProvider;
 import org.eclipse.ui.texteditor.MarkerAnnotation;
@@ -61,6 +65,7 @@ import org.eclipse.cdt.ui.text.ICPartitions;
 import org.eclipse.cdt.internal.core.model.IBufferFactory;
 
 import org.eclipse.cdt.internal.ui.text.IProblemRequestorExtension;
+import org.eclipse.cdt.internal.ui.util.EditorUtility;
 
 /**
  * A document provider for C/C++ content.
@@ -729,6 +734,15 @@ public class CDocumentProvider extends TextFileDocumentProvider {
 		} else if (element instanceof ITranslationUnitEditorInput) {
 			ITranslationUnitEditorInput input = (ITranslationUnitEditorInput)element;
 			original = input.getTranslationUnit();
+		} else if (element instanceof IAdaptable) {
+			IAdaptable adaptable= (IAdaptable)element;
+			ILocationProvider locationProvider= (ILocationProvider)adaptable.getAdapter(ILocationProvider.class);
+			if (locationProvider != null) {
+				IPath location= locationProvider.getPath(element);
+				if (location != null) {
+					original= createTranslationUnit(location);
+				}
+			}
 		}
 
 		if (original == null) {
@@ -768,6 +782,19 @@ public class CDocumentProvider extends TextFileDocumentProvider {
 		return tuInfo;
 	}
 
+	/**
+	 * Try to synthesize an ITranslationUnit out of thin air.
+	 * @param location  the file system location of the file in question
+	 * @return a translation unit or <code>null</code>
+	 */
+	private ITranslationUnit createTranslationUnit(IPath location) {
+		IEditorInput input= EditorUtility.getEditorInputForLocation(location, null);
+		if (input instanceof ITranslationUnitEditorInput) {
+			return ((ITranslationUnitEditorInput)input).getTranslationUnit();
+		}
+		return null;
+	}
+
 	/*
 	 * @see org.eclipse.ui.editors.text.TextFileDocumentProvider#disposeFileInfo(java.lang.Object,
 	 *      org.eclipse.ui.editors.text.TextFileDocumentProvider.FileInfo)

core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/util/EditorUtility.java

@@ -255,20 +255,6 @@ public class EditorUtility {
 		return null;
 	}
 
-	/**
-	 * Utility method to get an editor input for the given file system location.
-	 * If the location denotes a workspace file, a <code>FileEditorInput</code>
-	 * is returned, otherwise, the input is an <code>IStorageEditorInput</code>
-	 * assuming the location points to an existing file in the file system.
-	 * 
-	 * @param location  a valid file system location
-	 * @return an editor input
-	 * @deprecated Use {@link #getEditorInputForLocation(IPath, ICElement)} instead
-	 */
-	public static IEditorInput getEditorInputForLocation(IPath location) {
-		return getEditorInputForLocation(location, null);
-	}
-
 	/**
 	 * Utility method to open an editor for the given file system location
 	 * using {@link #getEditorInputForLocation(IPath, ICElement)} to create
@@ -306,16 +292,18 @@ public class EditorUtility {
 			// include paths
 			try {
 				ICProject[] projects = CCorePlugin.getDefault().getCoreModel().getCModel().getCProjects();
-				for (int i = 0; i < projects.length; i++) {
+				outerFor: for (int i = 0; i < projects.length; i++) {
 					IIncludeReference[] includeReferences = projects[i].getIncludeReferences();
 					for (int j = 0; j < includeReferences.length; j++) {
 						if (includeReferences[j].isOnIncludeEntry(location)) {
-							context = includeReferences[j].getCProject();
+							context = projects[i];
-							break;
+							break outerFor;
 						}
 					}
-					if (context != null)
+				}
-						break;
+				if (context == null && projects.length > 0) {
+					// last resort: just take any of them
+					context= projects[0];
 				}
 			} catch (CModelException e) {
 			}
@@ -329,10 +317,8 @@ public class EditorUtility {
 				if (unit != null) {
 					return new ExternalEditorInput(unit, new FileStorage(location));
 				}
-			}
+				// no translation unit - still try to get a sensible marker resource
-			// no translation unit - still try to get a sensible marker resource
+				// from the associated element
-			// from the associated element
-			if (cproject != null) {
 				IResource markerResource= cproject.getProject();
 				return new ExternalEditorInput(new FileStorage(location), markerResource);
 			}