[Rd] readBin(what="character", n=overcount)->extra "" in result (PR#9361)

[bill at insightful.com]

Full_Name: Bill Dunlap
Version: 2.4.0
OS: Windows XP
Submission from: (NULL) (208.252.71.182)


When I use readBin() to read an unknown number
of null-terminated strings from a file by supplying
an overcount as the n= argument, it appends an empty
string to the result.

> tf<-tempfile()
> strings<-c("One","Two","Three")
> writeBin(strings, con=tf)
> readBin(con=tf,what="character",n=100) # expect "One","Two","Three" only
[1] "One"   "Two"   "Three" ""     
> readBin(con=tf,what="integer",size=1,signed=FALSE,n=100)
 [1]  79 110 101   0  84 119 111   0  84 104 114 101 101   0
> unlink(tf)

> version
               _                           
platform       i386-pc-mingw32             
arch           i386                        
os             mingw32                     
system         i386, mingw32               
status                                     
major          2                           
minor          4.0                         
year           2006                        
month          10                          
day            03                          
svn rev        39566                       
language       R                           
version.string R version 2.4.0 (2006-10-03)