no output when unioning large numbers of shapes

Originator: YES

I have a feeling that this may be occuring due to paths with only one
node. There's one of these in the attachment at with a d value of
M 411.49681,313.58187 C 411.52754,313.56061 411.42263,313.56989
411.49681,313.58187 z
at roughly x=411.5px, y=738.8.

The path is REALLY tiny, it's only about 6 pixels long at 25600% zoom.

Originator: YES

actually, that's not true. The previous path doesn't union, however,
there's another one node path just near it that does:
d=M 387.84375 280.28125 C 387.88441 280.3658 388.11446 280.36457 387.84375
280.28125 z
This path has an id of path7692

the path in the previous comment has an id=path7804

Thanks for including an example file. Can you provide a list of steps for reproducing the issue using this file?

Steps to reproduce (with attachment):
1. Select all objects, ungroup completely
2. Select all brown objects
3. Path > Union
4. objects dissapear

Also works when only selecting some of the objects, sometimes works with smaller groups (~40-50 seems the max)

I'm running ubuntu hardy alpha5, with the standard inkscape install.

Here is a simpler example. Both paths in the file are single node paths. Both have the same style values in the XML, only their "d" values seem significant.

Try unioning the path on the bottom (either with itself, or the other path).

Also, try re-sizing both paths. THe top one resizes as per normal, but the bottom one doesn't seem to resize.

Also, the bottom one doesn't seem to display properly (it's a single node closed bezier curve, but it looks like it's got 4-13 straight sides, depending on the zoom scale).

Also reproduced on Windows XP, Inkscape r9497.

Hum same problem !
On linux Debian testing.

Inkscape 0.47 r22583, built Mar 12 2010

a fix has been committed to rev 12176, could you re-test to see if this is still a problem?

two test were performed:
1. Using the file InkscapeUnionBug.svg, it was found that the operation Path->Union caused one object to disappear, the other one was kept. The disappearance was related to the small size of the object. These shape operations have some numerical round-off error associated with them, and small objects may get misrepresented as empty. After reloading the file and scaling both objects uniformly by a factor of about 2 or so, it was found that both objects survived the Union operation.

2. File Inkscape Bug.svg. This file does not load correctly into current trunk. The loading problem is caused by the fact that there are two points with very large coordinates. The coordinates are:

         d="M 8.1269556e+17,-9.3570327e+17 L 8.1269556e+17,-9.3570327e+17 L 8.1269556e+17,-9.3570327e+17 z "
         d="M 8.634365e+17,5.0616653e+17 L 8.634365e+17,5.0616653e+17 L 8.634365e+17,5.0616653e+17 z "

After manually removing these two points, the attached file 'INKSCAPE BUGe17.svg' was obtained. This loads normally. To perform the Path->Union operation, all the objects were ungrouped, and all objects except the red background were selected for the Union. This led to 393 objects before the union, and a single Path with 2002 nodes after the Union. As far as I could tell visually, this Union was successful.

<off-topic>
On 2013-03-06 21:44 +0100, Alvin Penner wrote:
> 2. File Inkscape Bug.svg. This file does not load correctly into current trunk.

JFTR - based on quick tests with archived builds (32bit, Mac OS X 10.5.8, glib 2.28.2, cairo 1.10.2):
- trunk <= r10577 renders the file as expected
- trunk >= r10581 renders it empty
-> likely a change introduced with the merge of the "rendering cache branch (GSoC 2011)" in r10579:
<http://bazaar.launchpad.net/~inkscape.dev/inkscape/trunk/revision/10579>

I do not know whether this had been an intentional change [1], or a side-effect of the rendering cache code.
</off-topic>

> 2. File Inkscape Bug.svg. This file does not load correctly into current trunk.

yes, it is a very interesting rendering problem. If you load the file Inkscape Bug.svg and view it at a zoom level of about 50% and then perform Edit->Select All, then there are 2 outline rectangles that appear, both of which appear to be scaled reasonably according to the page size. Also, if you perform Object->Ungroup, then a large number of outline rectangles appear, all of which are scaled reasonably according to the page size. But at the same time the size of the scroll bar handle at the right side is extremely small, which would happen if the zoom level is extremely large.
     It is almost as if there are two different types of scaling going on here, one for the outline rectangles and one for the actual rendering.

Still success with INKSCAPE BUGe17.svg

Original file still opens as empty, though. But that was not the subject of the original report.

Arch Linux 64-bit, KDE Plasma 5
Inkscape 0.92pre1 15073 (GTK3)

Hi - thanks for reporting this bug, I've manually migrated it to Inkscape's new bug tracker on GitLab, and closed it here.

Please feel free to file new bugs about the issues you're seeing at
http://inkscape.org/report .

Moved to: https://gitlab.com/inkscape/inbox/issues/2164
Closed by: https://gitlab.com/greytomorrow