From paul at stat.auckland.ac.nz  Wed Feb 22 00:32:09 2017
From: paul at stat.auckland.ac.nz (Paul Murrell)
Date: Wed, 22 Feb 2017 12:32:09 +1300
Subject: [Rd] [FORGED] Re: Replaying a recorded plot (mixed base and
 grid) from pdf() in cairo_pdf() crashes R
In-Reply-To: <03c36881-6487-7446-2fc4-90458106cd68@stat.auckland.ac.nz>
References: <CANROs4dy7xvbYRAXHMQbrBjQiYrYgETUpBAAyPBk-rzOaNoWCA@mail.gmail.com>
	<CANROs4cd=EhVBsn25njQv7Uea+UHy=FqL18A-wOQ7pehmjXFjg@mail.gmail.com>
	<03c36881-6487-7446-2fc4-90458106cd68@stat.auckland.ac.nz>
Message-ID: <8f40e0c8-874b-f992-b5c5-38a46810ccf9@stat.auckland.ac.nz>

Hi

I decided to blame cairo_pdf().

There is a fix in r-devel (r72242) that works for the reported case, 
plus some basic sanity checks.

I could not complete 'make check-devel' because it was failing on 
reg-tests-1d.R ...

 > stopifnot(length(fd) == 10, identical(fd, format(dct <- 
as.POSIXct(dlt))))
Error: identical(fd, format(dct <- as.POSIXct(dlt))) is not TRUE

... anyone else seeing that ?

I would appreciate confirmation from a heavier user of cairo_pdf() that 
I have not broken anything.

Paul

On 21/02/17 08:27, Paul Murrell wrote:
> Hi
>
> This appears to be happening (at least) because cairo_pdf() delays
> initialising a Cairo surface until BM_NewPage(), rather than
> initiliasing a Cairo surface in BM_Open(), and replayPlot() triggers
> some activity (set clip region) on the device BEFORE a new page is
> started (so the pointer to the Cairo surface is null, so BOOM).
>
> Not sure yet whether to blame replayPlot() for not starting with a new
> page operation OR to blame cairo_pdf() for not initialising a Cairo
> surface at device startup.
>
> If anyone who knows more about Cairo (or cairo_pdf()) wants to point out
> a good reason for the way cairo_pdf() currently works, please don't hold
> back.
>
> Paul
>
> On 21/02/17 05:30, Yihui Xie wrote:
>> A quick follow-up: I just used cairo_pdf() as the recording device,
>> and it crashes R as well, so it is probably not relevant to pdf() but
>> an issue specific to cairo_pdf().
>>
>> cairo_pdf()
>> dev.control('enable')
>>
>> library("grid")
>> plot(1)
>> grid.text("A")
>>
>> res = recordPlot()
>> dev.off()
>>
>> cairo_pdf()
>> replayPlot(res)
>> dev.off()
>>
>>
>> Regards,
>> Yihui
>> --
>> https://yihui.name
>>
>>
>> On Mon, Feb 20, 2017 at 10:24 AM, Yihui Xie <xie at yihui.name> wrote:
>>> Hi,
>>>
>>> I wonder if this is expected or I'm doing a wrong thing.
>>>
>>> pdf()
>>> dev.control('enable')
>>>
>>> library("grid")
>>> plot(1)
>>> grid.text("A")
>>>
>>> res = recordPlot()
>>> dev.off()
>>>
>>> cairo_pdf()
>>> replayPlot(res)
>>> dev.off()
>>>
>>>
>>>  *** caught segfault ***
>>> address 0x4, cause 'memory not mapped'
>>>
>>>
>>>> sessionInfo()
>>> R version 3.3.2 (2016-10-31)
>>> Platform: x86_64-apple-darwin13.4.0 (64-bit)
>>> Running under: macOS Sierra 10.12.3
>>>
>>> locale:
>>> [1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8
>>>
>>> attached base packages:
>>> [1] stats     graphics  grDevices utils     datasets  methods   base
>>>
>>> loaded via a namespace (and not attached):
>>> [1] tools_3.3.2 yaml_2.1.14
>>>
>>> Regards,
>>> Yihui
>>> --
>>> https://yihui.name
>>
>> ______________________________________________
>> R-devel at r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-devel
>>
>

-- 
Dr Paul Murrell
Department of Statistics
The University of Auckland
Private Bag 92019
Auckland
New Zealand
64 9 3737599 x85392
paul at stat.auckland.ac.nz
http://www.stat.auckland.ac.nz/~paul/



[Rd] [FORGED] Re: Replaying a recorded plot (mixed base and grid) from pdf() in cairo_pdf() crashes R
Paul Murrell