The sound of the 4th semiquaver in A may initially raise doubts: it is devoid of an accidental and the 
raising d
2 to d2 is written only in the 2nd half of the bar (the 13th note). In spite of this, Chopin's mistake is almost certain:
- the previous chord is based on a G minor chord, in addition introduced by a D major chord, present throughout the entire bar. The fact that Chopin considered the sound of d to be obvious in this situation is supported by oversights of naturals before these notes both in the previous bar and in the discussed one. The use of d in the G minor (bar 141) and G7 (bar 142) chords is confirmed by d1 in bar 241 and d in bar 242, written correctly, with naturals, present in Morch in the viola and cello parts respectively;
-
d2 would have been accurate if the 1st half of the bar had been maintained in B minor – same as thanks to e2 we hear the 2nd half in C minor (see the next note).
The missing was added – most probably by Chopin – in the proofreading of FE2 (→EE). In turn, the absence of a respective correction in GE1 is puzzling, particularly in the carefully revised GE2. In the main text we omit the in the 2nd half of the bar, superfluous after an earlier sign in the bar.
Compare the passage in the sources »
category imprint: Interpretations within context; Differences between sources
issues: Omission of current key accidentals, Authentic corrections of FE, Inaccuracies in A
notation: Pitch