fcollapse with any missing weights returns all missing

[mcaceresb]

Consider

clear
set obs 10
gen x = _n
gen y = 1
replace y = . if mod(_n, 3) == 0
gen g = mod(_n, 5)

Missing weights should be dropped, but instead all the results are missing

. which fcollapse
/home/mauricio/ado/plus/f/fcollapse.ado
*! version 2.24.1 15jan2018

.     preserve

.         fcollapse x [fw = y], by(g)

.         l

     +-------+
     | g   x |
     |-------|
  1. | 0   . |
  2. | 1   . |
  3. | 2   . |
  4. | 3   . |
  5. | 4   . |
     +-------+

.     restore

.     collapse x [fw = y], by(g)

.     l

     +---------+
     | g     x |
     |---------|
  1. | 0   7.5 |
  2. | 1     1 |
  3. | 2   4.5 |
  4. | 3     8 |
  5. | 4     4 |
     +---------+

[sergiocorreia]

Agreed! I was skipping marksample on some cases, but it should be fixed now.