In FE, there is no raising c2 to c2. Visible traces of corrections in print reveal that it was a1 that was the original version; it was moved to the correct pitch in the proofreading, yet without . This patent oversight (of the engraver or of Chopin at the time of marking the correction) was revised both in GE and EE.
Compare the passage in the sources »
category imprint: Interpretations within context; Differences between sources; Corrections & alterations; Source & stylistic information
issues: EE revisions, Errors resulting from corrections, Terzverschreibung error, GE revisions, Omission of current key accidentals, Authentic corrections of FE
notation: Pitch