Reported as tidyverse/haven#551

Variables whose value labels appear on the label list prior to one with an empty value label are not assigned their value labels.

Step 1:

input x y z
0 0 0
end

lab def xlab 0 "Foo"
lab val x xlab

lab def ylab 0 "Bar"
lab val y ylab

lab def ylab 0 "", modify // This is one way to create an "empty" value label. It does *not* create a value label with an empty string for value 0.

lab def zlab 0 "FooBar"
lab val z zlab

label list
save example_input

Step 2: readstat example_input.dta example_output.dta

Actual example_output.dta :

Expected example_output.dta :

(Minor detail: the blueness of the 0 indicates the presence of an [empty] value label for variable y; I have no strong opinion on whether this value label should be preserved in the output file.)