Bug 219901 [Undo] new file creation subjec to Undo (file deleted without warning)
when creating a new file by right clicking on your project in the project explorer new->file this action is put on the undo/redo stack. Pressing Ctrl-Z to undo this action will thus delete your file. As this stack is separate from the stack in the editor , one can create a new file, work for a long time, then inadvertently press ctrl-z to undo a code change while having the focus on the project explorer and irrevocably lose their file. Redo will create a new EMPTY file; the work is gone, forever. This appears to only work for the "new file", not for "new->source file" etc. Although some may perceive this as a feature, it is hard to imagine a scenario where ctrl-z should permanently delete a file without warning.
bundles/org.eclipse.ui.ide/extensions/org/eclipse/ui/dialogs/WizardNewFileCreationPage.java
selectedResource = (IResource) ((IAdaptable) object)
							.getAdapter(IResource.class);
				}
				if (selectedResource != null) {
					if (selectedResource.getType() == IResource.FILE) {
						selectedResource = selectedResource.getParent();
					}
					if (selectedResource.isAccessible()) {
						resourceGroup.setContainerFullPath(selectedResource
								.getFullPath());
					}
				}
			}
		}
	}
	/**
	* Sets the flag indicating whether existing resources are permitted to be
	* specified on this page.
	* 
	* @param value
	*            <code>true</code> if existing resources are permitted, and
	*            <code>false</code> otherwise
	* @since 3.4
	*/
	public void setAllowExistingResources(boolean value) {
		if (resourceGroup == null) {
			initialAllowExistingResources = value;
		} else {
			resourceGroup.setAllowExistingResources(value);
		}