sprintf causes a segfault (PR#13613)
strangely enough, the way r handles the same sequence of expressions on
different occasions varies:
# fresh session 1
e = simpleError('foo')
sprintf('%s', e)
# segfault: address 0x202, cause memory not mapped
# ^c
sprintf('%s', e)
# error in sprintf("%s", e) : 'getEncChar' must be called on a CHARSXP
# fresh session 2
e = simpleError('foo')
sprintf('%s', e)
# segfault: address (nil), cause memory not mapped
# ^c
sprintf('%s', e)
# segfault, exit
note the difference in the address and how this relates to the outcome
of the second execution of sprintf('%s', e)
vQ
Waclaw.Marcin.Kusnierczyk at idi.ntnu.no wrote:
the following code illustrates a problem with sprintf which consistently causes
a segfault when applied to certain type of arguments. it also shows
inconsistent consequences of the segfault:
(e = tryCatch(stop(), error=identity))
# e is an error object
sprintf('%d', e)
# error in sprintf("%d", e) : unsupported type
sprintf('%f', e)
# error in sprintf("%f", e) : (list) object cannot be coerced to type
'double'
sprintf('%s', e)
# segfault reported, with a choice of options for how to exit the session
it is possible not to leave the session, by simply typing ^c (ctrl-c). (which
should probably be prohibited.) if one stays in the session, then trying to
evaluate sprintf('%s', e) will cause a segfault with immediate crash (r is
silently closed), but not necessarily if some other code is executed first. in
the latter case, there may be no segfault, but an error message might be printed
instead:
e = tryCatch(stop(), error=identity)
sprintf('%s', e)
# segfault, choice of options
# ^c, stay in the session
e = tryCatch(stop(), error=identity)
sprintf('%s', e)
# segfault, immediate exit
e = tryCatch(stop(), error=identity)
sprintf('%s', e)
# segfault, choice of options
# ^c, stay in the session
e = tryCatch(stop(), error=identity)
x = 1 # possibly, whatever code would do
sprintf('%s', e)
# [1] "Error in doTryCatch(return(expr), name, parentenv, handler): \n"
# [2] "Error in doTryCatch(return(expr), name, parentenv, handler): \n"
sprintf('%s', e)
# segfault, immediate exit
in the second code snippet above, on some executions the error message was
printed. on others a segfault caused immediate exit. (the pattern seems to
differ between 2.8.0 and 2.10.0-devel.)
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