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
/**
	 * Checks whether the linked resource target is valid. Sets the error
	 * message accordingly and returns the status.
	 * 
	 * @return IStatus validation result from the CreateLinkedResourceGroup
	 */
	protected IStatus validateLinkedResource() {
		IPath containerPath = resourceGroup.getContainerFullPath();
		IPath newFilePath = containerPath.append(resourceGroup.getResource());
		IFile newFileHandle = createFileHandle(newFilePath);
		IStatus status = linkedResourceGroup
				.validateLinkLocation(newFileHandle);
		if (status.getSeverity() == IStatus.ERROR) {
			if (firstLinkCheck) {
				setMessage(status.getMessage());
			} else {
				setErrorMessage(status.getMessage());
			}
		} else if (status.getSeverity() == IStatus.WARNING) {
			setMessage(status.getMessage(), WARNING);
			setErrorMessage(null);
		}
		return status;
	}
	/**
	 * Returns whether this page's controls currently all contain valid values.
	 * 
	 * @return <code>true</code> if all controls are valid, and
	 *         <code>false</code> if at least one is invalid
	 */