Tk Source Code

It is as in:

https://core.tcl.tk/tk/tktview?name=b601ce3ab1

Content of tmp. after 
"make test TESTFLAGS="-file imgPhoto.test -verbose bepst" > tmp." 
is:

>>
[...]
++++ imgPhoto-17.2 PASSED
---- imgPhoto-17.3 start
++++ imgPhoto-17.3 PASSED
++++ imgPhoto-18.1 SKIPPED: base64PackageNeeded
---- imgPhoto-18.2 start
*** Signal 9

Stop.
make: stopped in /usr/opt/tcl86/src/tk/unix
<<

I get System message:

>>
> swap_pager: out of swap space
> swap_pager_getswapspace(16): failed
<<

Although I have 2GB RAM and also so much swap space.

Merged to core-8-6-branch and trunk. Thanks!

Thank you, Keith, for the patch!

Since it's a fix of the fix, I have applied it on the branch previously used to deal with this bug, that is branch bug-b601ce3ab1 (warning: this is a branch off core-8-5-branch).

I tried it on Linux Debian 8 and on Windows. I ran successfully the standard command (skipping nonPortable tests), and also just the nonPortable tests (to check they still passs on my systems), i.e. with:

TESTFLAGS="-file imgPhoto.test -verbose beps -constraints nonPortable -limitconstraints true"

Thank you for your analysis and patch to come.

IMO the 'knownBug' constraint is inadequate here because (from tcltest man page) it means that the bug corresponding to the test is hot not yet fixed. This is not the case.

I wanted to suggest creation of a new constraint 'hasAtLeast4GBmem', or similarly named, that would be assessed at runtime from the available free system memory, but then I realized that there is no way I know of to get the necessary info at script level (without resorting to platform-dependent tricks at least).

So I suggest using 'nonPortable' instead of 'knownBug'. From its description in the tcltest tallest man page it seems adapted to the case.

The bug is:
If there is insufficient memory, the error message
"not enough free memory for image buffer" should be returned.
Instead, some systems (e.g. FreeBSD 11.1) terminate the test interpreter.

This ticket relates to this bug report on c.l.t. -
https://groups.google.com/forum/#!topic/comp.lang.tcl/fuz94EZ04Ps
"Tcl8.6.7 failed Tests on FreeBSD 11.1"

@fvogel

I believe bug [b601ce3ab1] is fixed, the problem here is in the tests.  I will post a patch for the tests shortly.  Tests 18.1 to 18.3 will request much less memory.  Tests 18.7 to 18.9 will continue to request multi-Gb but will have the constraint "knownBug".

In detail:

The tests for [b601ce3ab1] accidentally expose a separate bug related to memory allocation.

Tk allocates a buffer according to the size requested by the header of the GIF image.  If the image is corrupt or malicious, it may request a very large size.  If the buffer is successfully allocated, and then the corrupt image fails to load, Tk then frees the memory, and the Tk command returns with error status as expected by the test.

When there is insufficient memory on Linux and Windows systems, the Tk command returns with error status and the message "not enough free memory for image buffer" - this error message is defined in generic/tkImgPhoto.c.

On FreeBSD 11.1 this allocation error appears not to be trapped, and the Tcl process is terminated.  I do not have sufficient knowledge of memory allocation in Tcl/Tk to determine whether this is a bug in Tk or a limitation of FreeBSD's malloc.

Cannot reproduce this on Linux Debian 8 (real machine, not a VM) with 8 Gb memory.

Memory usage climbs to 3.4 Gb during these tests.

Hypotheses:

- Perhaps the test should be constrained to run only on machines featuring large amounts of memory

- Perhaps the test should be reworked to require less memory to run

- Perhaps bug [b601ce3ab1] is not fixed after all (I doubt)