Issue 107521 - edit points on curve: smooth points may change to corner type
Summary: edit points on curve: smooth points may change to corner type
Alias: None
Product: Draw
Classification: Application
Component: editing (show other issues)
Version: 3.4.1
Hardware: PC Linux, all
: P3 Trivial (vote)
Target Milestone: ---
Assignee: AOO issues mailing list
QA Contact:
Keywords: needmoreinfo
Depends on:
Reported: 2009-12-08 05:30 UTC by Joe Smith
Modified: 2013-06-10 16:21 UTC (History)
2 users (show)

See Also:
Issue Type: DEFECT
Latest Confirmation in: ---
Developer Difficulty: ---

Sample document showing problem (7.65 KB, application/
2009-12-30 16:37 UTC, Joe Smith
no flags Details

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Description Joe Smith 2009-12-08 05:30:11 UTC
In OOo Draw, Bézier curves can have points of three different types: Corner,
Smooth and Symmetric. Using the "Edit Points" toolbar, it is possible to change
selected points to any of the three types.

A point's type should be stable: once set, the point's type should remain the
same until the user changes it to a different type.

This does not seem to be the case with recent versions of OOo. A point's type is
/usually/ stable, but after some editing operations, it often spontaneously
changes to a corner point. Sometimes several points on a curve will change to
corner points.

Unfortunately, I haven't found a recipe that will always show the problem, but
if I...
1) create a horizontal line,
2) Edit Points,
3) add a point near the center,
4) select the new point and click the "Smooth Transition" button,
5) fiddle with the curve for a while (move points, handles, move the shape,
select/de-select the shape), eventually, the center point will spontaneously
change from smooth to corner mode.

This can be a real problem for a curve with many points because switching from a
corner point back to a smooth point may change the position of the control
points, leading to a lot of repeated editing.
Comment 1 wolframgarten 2009-12-08 07:40:42 UTC
Sorry, not reproducible here. Do you really use 3.1.1 RC2? I would recommend to
use the final version or the current 3.2 version...
Comment 2 Joe Smith 2009-12-08 15:34:33 UTC
> Do you really use 3.1.1 RC2?
Reported against: 3.1  310m18(Build:9417), which I believe is
RC2, but it doesn't matter: I see the same problem in every recent version. I
can reproduce it at them moment, testing 2.4.2, 3.1.1 and OOO320_m6 and DEV300_m65.

Here's a screencast showing the problem as it appears for me:
Comment 3 Joe Smith 2009-12-30 16:37:04 UTC
Please have a look at the attached file.

1) Select the curve
2) Enter "Edit points" mode
3) Select the center point
Note that the "Edit points" toolbar shows it as a corner point.
4) Click on the "Smooth transition" button
Instead of changing the point's control mode, it remains a corner point.

You'll have to take my word that this was a normally-functioning "smooth" point
just before I saved this file: the toolbar showed "smooth" and the control
points were moving together. While making random edits of the normal point, I
found that it had spontaneously changed to a corner point: the control points
moved independently. So I did Edit > Undo to restore the curve to the state
before I moved the control point, and saved the file.

Looking at the document xml, I see that the point state (smooth/corner) is not
explicit in the curve data. So I assume that it has to be calculated from the
data and depends on whether the control points and the point on the curve are
collinear. Perhaps there is a problem with this calculation--e.g., when integer
coordinates are not perfectly collinear, or there is some round-off
inequality--and the calculation fails even though the three points are as close
to "smooth" as possible.

If there's something else I can try to help isolate the problem, please let me know.
Comment 4 Joe Smith 2009-12-30 16:37:57 UTC
Created attachment 66919 [details]
Sample document showing problem
Comment 5 Rob Weir 2013-02-02 02:54:46 UTC
This Issue requires more information ('needmoreinfo'), but has not been updated
within the last year. Please provide feedback as requested and re-test with the the latest version of OpenOffice - the problem(s) may already be addressed. 

You can download Apache OpenOffice 3.4.1 from

Please report back the outcome of your testing, so this Issue may be closed or
progressed as necessary - otherwise the issue may be Resolved as Invalid in the
Comment 6 Joe Smith 2013-02-03 02:15:02 UTC
(In reply to comment #3)
> Please have a look at the attached file.
> ...

I still see this problem as described in #3 above testing AOO 3.4.1 on Fedora 17.
Comment 7 Joe Smith 2013-02-05 15:35:05 UTC
Re-tested with nightly:
AOO350m1(Build:9611)  -  Rev. 1442201

Problem still exists following steps in description.
Comment 8 Armin Le Grand 2013-06-10 16:21:06 UTC
ALG: Grepping