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/src/org/eclipse/ui/wizards/newresource/BasicNewProjectResourceWizard.java
else
			message = NLS.bind(
					ResourceMessages.NewProject_perspSwitchMessageWithDesc,
					new String[] { finalPersp.getLabel(), desc });
		MessageDialogWithToggle dialog = MessageDialogWithToggle
				.openYesNoQuestion(window.getShell(),
						ResourceMessages.NewProject_perspSwitchTitle, message,
						null ,
						false , store,
						IDEInternalPreferences.PROJECT_SWITCH_PERSP_MODE);
		int result = dialog.getReturnCode();
		
		if (dialog.getToggleState()) {
			String preferenceValue;
			if (result == IDialogConstants.YES_ID) {
				
				
				preferenceValue = IWorkbenchPreferenceConstants.OPEN_PERSPECTIVE_REPLACE;
			} else {
				preferenceValue = IWorkbenchPreferenceConstants.NO_NEW_PERSPECTIVE;
			}
			
			PrefUtil.getAPIPreferenceStore().setValue(
					IDE.Preferences.PROJECT_OPEN_NEW_PERSPECTIVE,
					preferenceValue);
		}
		return result == IDialogConstants.YES_ID;
	}
}