Too long pathname in bitmap() crashes R on WinXP

It is also possible to trigger this on Unix: a buffer in postscript() is
PATH_MAX when it should be 2*PATH_MAX + 2.

I'll fix this in 2.5.0 alpha (there is also a potential issue inside the
Windows' runcmd that needs fixing).

On Fri, 30 Mar 2007, Henrik Bengtsson wrote:

Hi,

using too long pathnames for bitmap() crash R on WinXP.  I've verified
that this is the case with R version 2.4.1 Patched (2007-03-25 r40958)
and R version 2.5.0 alpha (2007-03-30 r40957). I cannot reproduce it
on Linux.

REPRODUCIBLE EXAMPLE:

% Rterm --vanilla

# Tell R where Ghostscript is
gsexe <- "C:/gs/gs8.54/bin/gswin32c.exe";
gsexe <- "C:/Program Files/gs/gs8.56/bin/gswin32c.exe";
gsexe <- shortPathName(gsexe);
Sys.putenv("R_GSCMD"=gsexe);

# Total length of pathname (R crashes when it is too long)
n <- 130;

# Output path
path <- tempdir();

# Filename
name <- paste(rep("a", n-5-nchar(path)), collapse="");
filename <- paste(name, "png", sep=".");

# Full pathname
pathname <- file.path(path, filename);
print(pathname);
stopifnot(nchar(pathname) == n);

bitmap(pathname);
plot(1);
dev.off();

R crash with dev.off(), but the PNG file is still created.


# MORE DETAILED EXAMPLE:

n <- 130;
path <- tempdir();
name <- paste(rep("a", n-5-nchar(path)), collapse="");
filename <- paste(name, "png", sep=".");
pathname <- file.path(path, filename);
print(pathname);

# Tell R where Ghostscript is
gsexe <- "C:/gs/gs8.54/bin/gswin32c.exe";
gsexe <- "C:/Program Files/gs/gs8.56/bin/gswin32c.exe";
gsexe <- shortPathName(gsexe);

cmd <- paste(gsexe, " -dNOPAUSE -dBATCH -q -sDEVICE=png256 -r72
-g432x432 -sOutputFile=", pathname, sep="");
print(cmd);
print(nchar(cmd));

tmp <- tempfile();
postscript(file=tmp, width=6, height=6, pointsize=9, paper="special",
horizontal=FALSE, print.it=TRUE, command=cmd);
plot(1);
dev.off();

It seems to have to do with the length of 'cmd' (since the possible
pathname length varies with the length of 'gsexe' used).

Any ideas?

/Henrik

--
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
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