On 23.02.2016 11:37, Martin Maechler wrote: >>>>>> nospam@altfeld-im de <nos...@altfeld-im.de> >>>>>> on Mon, 22 Feb 2016 18:45:59 +0100 writes: > > > Dear R developers > > I think I have found a bug that can be reproduced with two lines of code > > and I am very thankful to get your first assessment or feed-back on my > > report. > > > If this is the wrong mailing list or I did something wrong > > (e. g. semi "anonymous" email address to protect my privacy and defend > > unwanted spam) please let me know since I am new here. > > > Thank you very much :-) > > > J. Altfeld > > Dear J., > (yes, a bit less anonymity would be very welcomed here!), > > You are right, this is a bug, at least in the documentation, but > probably "all real", indeed, > > but read on. > > > On Tue, 2016-02-16 at 18:25 +0100, nos...@altfeld-im.de wrote: > >> > >> > >> If I execute the code from the "?write.table" examples section > >> > >> x <- data.frame(a = I("a \" quote"), b = pi) > >> # (ommited code) > >> write.csv(x, file = "foo.csv", fileEncoding = "UTF-16LE") > >> > >> the resulting CSV file has a size of 6 bytes which is too short > >> (truncated): > >> > >> """,3 > > reproducibly, yes. > If you look at what write.csv does > and then simplify, you can get a similar wrong result by > > write.table(x, file = "foo.tab", fileEncoding = "UTF-16LE") > > which results in a file with one line > > """ 3 > > and if you debug write.table() you see that its building blocks > here are > file <- file(........, encoding = fileEncoding) > > a writeLines(*, file=file) for the column headers, > > and then "deeper down" C code which I did not investigate.
I took a look at connections.c. There is a call to strlen() that gets confused by null characters. I think the obvious fix is to avoid the call to strlen() as the size is already known: Index: src/main/connections.c =================================================================== --- src/main/connections.c (revision 70213) +++ src/main/connections.c (working copy) @@ -369,7 +369,7 @@ /* is this safe? */ warning(_("invalid char string in output conversion")); *ob = '\0'; - con->write(outbuf, 1, strlen(outbuf), con); + con->write(outbuf, 1, ob - outbuf, con); } while(again && inb > 0); /* it seems some iconv signal -1 on zero-length input */ } else > > But just looking a bit at such a file() object with writeLines() > seems slightly revealing, as e.g., 'eol' does not seem to > "work" for this encoding: > > > fn <- tempfile("ffoo"); ff <- file(fn, open="w", encoding = "UTF-16LE") > > writeLines(LETTERS[3:1], ff); writeLines("|", ff); writeLines(">a", ff) > > close(ff) > > file.show(fn) > CBA|> > > file.size(fn) > [1] 5 > > With the patch applied: > readLines(fn, encoding="UTF-16LE", skipNul=TRUE) [1] "C" "B" "A" "|" ">a" > file.size(fn) [1] 22 - Mikko Korpela > >> The problem seems to be the iconv function: > >> > >> iconv("foo", to="UTF-16") > >> > >> produces > >> > >> Error in iconv("foo", to = "UTF-16"): > >> embedded nul in string: '\xff\xfef\0o\0o\0' > > but this works > > > iconv("foo", to="UTF-16", toRaw=TRUE) > [[1]] > [1] ff fe 66 00 6f 00 6f 00 > > (indeed showing the embedded '\0's) > > >> In 2010 a (partial) patch for this problem was submitted: > >> http://tolstoy.newcastle.edu.au/R/e10/devel/10/06/0648.html > > the patch only related to the iconv() problem not allowing 'raw' > (instead of character) argument x. > > ... and it is > 5.5 years old, for an iconv() version that was less > featureful than today. > Rather, current iconv(x) allows x to be a list of raw entries. > > > >> Are there chances to fix this problem since it prevents writing Windows > >> UTF-16LE text files? > > >> > >> PS: This problem can be reproduced on Windows and Linux. > > indeed.... also on "R devel of today". > > I agree it should be fixed... but as I said not by the patch you > mentioned. > > Tested patches to fix this are welcome, indeed. ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel