Empasize.cols and emphasize.rows alters the data for empty cells

[romantseg]

While I was working on more tests, I saw an odd behavior that seems to be a bug

> df <- data.frame(a=c("", 1, 1), b=1:3, c=c("", "", 2))
> pander(df)

-----------
 a   b   c 
--- --- ---
     1     

 1   2     

 1   3   2 
-----------

> pander(df, emprashize.cols = 1, emphasize.rows = c(1,2))

-----------
 a   b   c 
--- --- ---
        *2*

*1* *1*    

 1   3   2 
-----------

I added it to not forget to have a look at it later

[romantseg]

After a bit more investigation it turns out that the problem is this line.

Problem is that apply for rows returns a transposed data.frame which can't be assigned back. For example,

> df <- data.frame(a=1:3, b=1:3, c=1:3)
> apply(df[c(1,2),,drop=F], c(1), identity)
  1 2
a 1 2
b 1 2
c 1 2
> df[c(1,2),] <- apply(df[c(1,2),,drop=F], c(1), identity)
> df
  a b c
1 1 1 2
2 1 2 2
3 3 3 3

Looking at documentation for apply, it seems to be consistent

If each call to FUN returns a vector of length n, then apply returns an array of dimension c(n, dim(X)[MARGIN]) if n > 1.

So it seems that when apply is only used for rows it should be transposed before assigning back

@daroczig , what do you think?