Just came across this, possibly related to #1257.
one <- data.frame(fü=1:3, bar=1:3)
two <- data.frame(fü=1:3, bar=1:3)
names(one) == names(two)
bind_rows(one, two)
Encoding(names(one)[1]) <- "UTF-8"
names(one) == names(two)
bind_rows(one, two) # three columns!
Just came across this, possibly related to #1257.