Chopin initially wrote the c
3 note in the 2nd quaver in the bar as d
3, which required the use of 
for the next quaver (d3). After changing the 2nd quaver to c3, this already superfluous was not removed, while the editions supplemented it with a to d2. In the main text we do not include these accidentals.
Compare the passage in the sources »
category imprint: Differences between sources; Editorial revisions; Corrections & alterations; Source & stylistic information
issues: Corrections in A, Errors resulting from corrections, GE revisions, Cautionary accidentals, Enharmonic corrections
notation: Pitch