[Rd] bug in rbind.data.frame with factors (PR#8868)

[rafalku at gmail.com]

Full_Name: Rafal Kustra
Version: 2.1.1
OS: Linux, MacOS 10.3
Submission from: (NULL) (69.195.47.62)


When Rbinding two data frames with factors, strange result occur (but no error)
when the order of data frame variables is different in two data frames:

> d1=as.data.frame(list(x=1:10,y=letters[1:10]))
> d2=as.data.frame(list(y=LETTERS[1:5],x=7:11))
> d2
  y  x
1 A  7
2 B  8
3 C  9
4 D 10
5 E 11
> rbind(d1,d2)
    x    y
1   1    a
2   2    b
3   3    c
4   4    d
5   5    e
6   6    f
7   7    g
8   8    h
9   9    i
10 10    j
11  7 <NA>
21  8 <NA>
31  9 <NA>
41 10 <NA>
51 11 <NA>
Warning message:
invalid factor level, NAs generated in: "[<-.factor"(`*tmp*`, ri, value = c("A",
"B", "C", "D", "E")) 


Things work correctly when the order of variables is the same:

> d3=as.data.frame(list(x=7:11,y=LETTERS[1:5]))
> rbind(d1,d3)
    x y
1   1 a
2   2 b
3   3 c
4   4 d
5   5 e
6   6 f
7   7 g
8   8 h
9   9 i
10 10 j
11  7 A
21  8 B
31  9 C
41 10 D
51 11 E
>