The trilled note in A is an erroneous c2. A similar mistake, consisting in writing the upper second of the trilled note instead of the trilled note, while the performance of the trill begins from the upper second, was committed by Chopin also in the Bolero, Op. 19, bar 187 and in the Sonata in B
minor, 3rd mov., bar 20. In GE1 (→FE→EE) the error was corrected, probably by Chopin, whereas GE2 returned to the erroneous text of A. See also the note in the next bar.
In the main text we add a cautionary 
before b1.
Compare the passage in the sources»
category imprint: Differences between sources
issues: Errors in GE, GE revisions, Errors of A, Authentic corrections of GE
notation: Pitch