extruder: problem with shared nodes

[skyper]

What steps will reproduce the problem?

1. Draw two rectified rectangle closed ways with one overlapping segment and two nodes in common.
2. extrude (single align) on side with one shared node of one area to the inside

What is the expected result?

The shared node remains only part of the untouched area and a new shared node is created at the new corner or the opposite considerering ids (new <-> old).

What happens instead?

The shared node remains shared and a new node only connected to the changed area is created.

Please provide any additional information below. Attach a screenshot if possible.

I changed the settings for "ignore-shared-nodes" but it did not change anything.

Have a look at attached example file​.

Repository Root: http://josm.openstreetmap.de/svn
Build-Date: 2014-07-20 01:36:10
Last Changed Author: stoecker
Revision: 7318
Repository UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
URL: http://josm.openstreetmap.de/svn/trunk
Last Changed Date: 2014-07-19 21:12:28 +0200 (Sat, 19 Jul 2014)
Last Changed Rev: 7318

Identification: JOSM/1.5 (7318 en) Linux Debian GNU/Linux 7.6 (wheezy)
Memory Usage: 259 MB / 882 MB (126 MB allocated, but free)
Java version: 1.7.0_55, Oracle Corporation, OpenJDK 64-Bit Server VM
Java package: openjdk-7-jre:amd64-7u55-2.4.7-1~deb7u1
VM arguments: [-Djosm.home=/tmp/.josm]
Program arguments: [--language=en, extrude_ex2.osm]
Dataset consistency test: No problems found

[skyper]

sample file

[skyper]

screenshot

[akks]

I got another result from "before" part of example osm-file:

[akks]

correct attachement

[akks]

Is this result correct? (or the node ids should be checked?)

[skyper]

Replying to akks:

Is this result correct? (or the node ids should be checked?)

I did not check the node ids, so far. Would be the next step.

Your example is about extruding to the outside while I am talking about extruding to the inside, e.g. smaller size.

[akks]

Oh, sorry. Looking again...

[akks]

Reproduced and located the code: https://josm.openstreetmap.de/browser/josm/trunk/src/org/openstreetmap/josm/actions/mapmode/ExtrudeAction.java#L633

Looking for fix...

[Hojoe]

That's a rounding problem. If the epsilon is larger, then it seems to work. I add a small patch with a epsion of 1e-2. I hope this helps.

[bastiK]

In 7791/josm:

see #10286 - add test for Geometry class

[bastiK]

1e-2 is 5 degrees. That's too large and probably has unwanted consequences.

The rounding error comes from Geometry.getLineLineIntersection as the test in [7791] demonstrates.

[bastiK]

In 7792/josm:

see #10286 - fix numerical rounding problems

[bastiK]

Rounding error is fixed, but the original problem remains for me.