Before the 5th, 15th, 19th and 23rd semiquaver in GC (→GE1) and FE there is no accidental, so all of them should be interpreted as a2. In the 2nd half of the bar it is certainly erroneous, which induced the reviser of GE2 (→GE3) to consider the whole bar as an example of overlooking the sign of the current key and adding a 
already next to the first of the aforementioned notes. A flat in this place is present also in EE, which could generally correspond to Chopin's notation in the base text to this edition. According to us, it is, however, more likely that in EE we are also dealing with an intervention of the reviser:
-
in a similar melodic turn in bar 48 the 5th semiquaver is an e
2, moreover, in the sources there is no 
returning e2 in the 2nd half of the bar; -
Chopin undoubtedly heard a
2 only in the 2nd half of the bar, where it is obvious due to A in the bass. Therefore, the first half of the bar could have been written faultlessly, although in a confusing manner, if we take into consideration the A major key, reaffirmed in the previous bar.
Compare the passage in the sources »
category imprint: Interpretations within context; Differences between sources
issues: EE revisions, GE revisions, Omission of current key accidentals
notation: Pitch