Wrong rendering of way labels in persian font, only at specific zoom levels

[Don-vip]

Weird rendering problem found while debugging #12025

What steps will reproduce the problem?

1. Make sure advanced preference mapppaint.nameOrder starts with name
2. Load ​osmwww:way/4430932
3. Zoom out

What is the expected result?

1. Persian name is displayed correctly at each zoom level

What happens instead?

1. Rendering problems only at certain zoom levels, see below

Revision: 8966
Is-Local-Build: true
Build-Date: 2015-10-29 19:02:49

Identification: JOSM/1.5 (8966 SVN en) Windows 7 64-Bit
Memory Usage: 546 MB / 2708 MB (175 MB allocated, but free)
Java version: 1.8.0_66, Oracle Corporation, Java HotSpot(TM) 64-Bit Server VM
VM arguments: [-Dfile.encoding=UTF-8]
Program arguments: [--debug]
Dataset consistency test: No problems found

Plugins:
- apache-commons (31718)
- geotools (31603)
- imagery-xml-bounds (31694)
- jts (31603)
- opendata (31695)
- utilsplugin2 (31694)

[Don-vip]

Paul, do you have an idea what's going on here? Is it the same behaviour on Linux?

[Don-vip]

Mmm with exact same data and zoom levels I can't reproduce the problem anymore. Is there some font cache involved in text rendering?

[Mesgary]

I can not reproduce the bug. I don't know why it has happened to you!
Here you can see my info.

Revision: 8964
Repository Root: http://josm.openstreetmap.de/svn
Relative URL: ^/trunk
Last Changed Author: simon04
Last Changed Date: 2015-10-27 23:40:20 +0100 (Tue, 27 Oct 2015)
Build-Date: 2015-10-28 02:32:10
URL: http://josm.openstreetmap.de/svn/trunk
Repository UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last Changed Rev: 8964

Identification: JOSM/1.5 (8964 en) Mac OS X 10.11
Memory Usage: 392 MB / 910 MB (107 MB allocated, but free)
Java version: 1.8.0_60, Oracle Corporation, Java HotSpot(TM) 64-Bit Server VM
VM arguments: [-Djava.library.path=/Applications/JOSM.app/Contents/MacOS, -DLibraryDirectory=/Users/mesgary/Library, -DDocumentsDirectory=/Users/mesgary/Documents, -DApplicationSupportDirectory=/Users/mesgary/Library/Application Support, -DCachesDirectory=/Users/mesgary/Library/Caches, -DSandboxEnabled=false, -Dapple.laf.useScreenMenuBar=true, -Dcom.apple.macos.use-file-dialog-packages=true, -Dcom.apple.macos.useScreenMenuBar=true, -Dcom.apple.mrj.application.apple.menu.about.name=JOSM, -Dcom.apple.smallTabs=true]
Dataset consistency test: No problems found

Plugins:
- measurement (31694)

[Don-vip]

I think it may be specific to Windows.

[Mesgary]

I can not check it with windows because my laptop which has windows runs with an older java version and due to sanction it is hard to update it

[bastiK]

Cannot reproduce on Linux.

When zooming in, the font size of text along the way changes from 9 to 10, 11 and finally to 12. It looks as if font size 9 and 12 works fine, but in between, something goes wrong. Maybe a broken font file or a Java bug?

[Hb---]

Cannot reproduce on Windows.

[Don-vip]

Cannot reproduce anymore (Win10, Java 8u172, JOSM r13816).