[Rd] Rgui.exe plot device "Save as" crash (PR#9237)

[mwtoews at sfu.ca]

Full_Name: Michael Toews
Version: 2.3.1
OS: WindowsXP Home/Proffesional SP2
Submission from: (NULL) (142.58.206.114)


Hi,
I have a bug that I can reproduce on two different MS Windows platforms
(1:AMD64x2/WinXP SP2 Home; 2:P4/WinXP SP2 Prof.) which is triggered by the "Save
as" dialog when saving a plot from a Windows device onto the Desktop. This bug
is difficult to reproduce, but here are some instructions to attempt a crash:
1) Start R from Start menu
2) Plot something simple, such as "plot(1:5)"
3) Choose "File > Save as PDF"
4) In the dialog, click the "Save in:" drop-down menu at the top, and select
"Desktop"
5) Type "boohoo" in the "File name:" field, and click "Save"
6) Repeat steps 3 and 4, but try to not hover the mouse over any files or window
controls, except for "boohoo.pdf" (although this isn't always the case). If you
don't crash, repeat steps 3 to 5 again until a crash.
7) *crash*; Windows will display the default crash dialog; Rgui.exe will appear
in the Windows Task Manager (ctrl-alt-del in Processes tab) using about 0 of
CPU.
8) Click "Don't Send" from the dialog
9) Observe that "Rgui.exe" is now using all available CPU resources for that
thread (this is about 50 for Hyper-threading-enabled or dual-core CPUs). It is
probably in an infinite loop.
10) Choose "Rgui.exe" from the Processes in Windows Task Manager, and click "End
Process". Now your system will be stable, and you can repeat the bug, if you
wish.

Here are some things that do _not_ affect the outcome:
- Presence or absence of a custom .Rprofile in C:\Program Files\R\R-2.3.1, or
Rconsole in "My Documents"
- The use of a different file name in step 5; I have also tried "tmp" and "rat a
tat tat", so spaces don't seem to matter
- The complexity of the plot
- Active or inactive Windows devices
- MDI or SDI modes for GUI

Here are some things that _do_ affect the outcome:
- No crash if you "Save as" any of the Jpeg options, but crash for all of the
other formats (Metafile, Postscript, etc.)
- No crash if in other folder, such as "My Documents"; this crash seems to
happen only in the Desktop folder when accessed through the drop-down list at
the top or the button on the left-hand side (oddly enough, when navigating an
absolute path from C:\Documents and Settings\etc..\Desktop, there is no crash)
- In the "Save as" dialog, if you navigate to the Desktop folder by selecting
the button on the left-hand side of the dialog (rather than in the "Save in:"
drop-down field as indicated in step 4), the crash does _not_ trigger the
default Microsoft crash dialog, and Rgui.exe silently crashes (disappears), but
remains as an active process, using ~ 50% of CPU resources, and requires a
manual "End Process".
- If "Debug" (if available) or "Send Report [to Microsoft]" are pressed in the
crash dialog, the Rgui.exe process ends normally, and no manual "End Process" is
required.

Sorry if this seems "TooMuchAtOnce", but it is all the same bug with lots of
details. My guess is it has something to do with the Tooltip from the Windows
system "Save as" dialog, which suggests there is a bug in R's implementation of
the system "Save as" dialog. As well, it appears to have problems with the
"Desktop" folder when navigated from the convenient "Desktop" links (either from
the upper drop-down list or left-hand button) in the "Save" dialog.

I don't have access to a pre-compiled Win32 EXE of the the R 2.4.0 alpha
releases, otherwise I would try to trigger this bug on the upcoming release.