18. The non-transitory computer-readable storage medium of claim 17 , further comprising: one or more second entries, each second entry containing information identifying a character received as textual user input corresponding to an editing action identified by the information contained by a first entry, such that the content of the second entries are usable to replay to the first buffer the textual user input characters whose editing actions are incompatible with application text changes to the second buffer in response to reconciliation to the first buffer of the application text changes to the second buffer.
17. A non-transitory computer-readable storage medium storing a text synchronization data structure relating to a first buffer, (1) textual user input having been applied to the first buffer, and (2) application text changes synchronized from a second buffer having been applied to the first buffer, the data structure comprising: one or more first entries, each first entry containing information identifying an editing action that (a) has been applied to the first buffer in response to textual user input, (b) has been communicated to the second buffer, and (c) has not been acknowledged by the second buffer, such that the contents of the first entries are usable to reverse editing actions that have been applied to the first buffer and are incompatible with application text changes to the second buffer.