[R] readLines without skipNul=TRUE causes crash

[Martin Maechler]

>>>>> Anthony Damico <ajdamico at gmail.com>
>>>>>     on Sun, 16 Jul 2017 06:40:38 -0400 writes:

    > hi, the text file that prompts the segfault is 4gb but only 80,937 lines
    >> file.info( "S:/temp/crash.txt")
    > size isdir mode               mtime
    > ctime               atime exe
    > S:/temp/crash.txt 4078192743 FALSE  666 2017-07-15 17:24:35 2017-07-15
    > 17:19:47 2017-07-15 17:19:47  no


    > On Sun, Jul 16, 2017 at 6:34 AM, Duncan Murdoch <murdoch.duncan at gmail.com>
    > wrote:

    >> On 16/07/2017 6:17 AM, Anthony Damico wrote:
    >> 
    >>> thank you for taking the time to write this.  i set it running last
    >>> night and it's still going -- if it doesn't finish by tomorrow, i will
    >>> try to find a site to host the problem file and add that link to the bug
    >>> report so the archive package can be avoided at least.  i'm sorry for
    >>> the bother
    >>> 
    >>> 
    >> How big is that text file?  I wouldn't expect my script to take more than
    >> a few minutes even on a huge file.
    >> 
    >> My script might have a bug...
    >> 
    >> Duncan Murdoch
    >> 
    >> On Sat, Jul 15, 2017 at 4:14 PM, Duncan Murdoch
    >>> <murdoch.duncan at gmail.com <mailto:murdoch.duncan at gmail.com>> wrote:
    >>> 
    >>> On 15/07/2017 11:33 AM, Anthony Damico wrote:
    >>> 
    >>> hi, i realized that the segfault happens on the text file in a
    >>> new R
    >>> session.  so, creating the segfault-generating text file requires
    >>> a
    >>> contributed package, but prompting the actual segfault does not --
    >>> pretty sure that means this is a base R bug?  submitted here:
    >>> https://bugs.r-project.org/bugzilla3/show_bug.cgi?id=17311
    >>> <https://bugs.r-project.org/bugzilla3/show_bug.cgi?id=17311>
    >>> hopefully i am not doing something remarkably stupid.  the text file itself
    >>> is 4GB
    >>> so cannot upload it to bugzilla, and from the
    >>> R_AllocStringBugger error
    >>> in the previous message, i think most or all of it needs to be
    >>> there to
    >>> trigger the segfault.  thanks!

In the mean time, communication has continued a bit at the bugzilla bug tracker
(https://bugs.r-project.org/bugzilla3/show_bug.cgi?id=17311 ), and
as you can read there, the bug is fixed now, also thanks to an
initial patch proposal by Hannes Mühleisen.

Martin Maechler
ETH Zurich (and R Core)