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<font size="+1">I'm working on this bug :
<a class="moz-txt-link-freetext" href="https://bugs.freedesktop.org/show_bug.cgi?id=33090">https://bugs.freedesktop.org/show_bug.cgi?id=33090</a><br>
</font><span id="summary_alias_container"><span
id="short_desc_nonedit_display">"Thai text in some UI elements
will be displayed overlapped on Windows Vista / Windows 7"<br>
<br>
</span></span><font size="+1">I've tried debugging the bug. Note:
You must set the Option to “use system font for user interface”
and the system font must not have Thai glyph (such as Segoe UI) so
fallback mechanism kick-in.<br>
<br>
Here's the steps I've tried.<br>
<br>
1) First attach the debugger to the LO process, then <br>
<br>
2) In Writer, choose File > Properties > Description tab
> Title box, type<br>
กิน<br>
(Using Thai keyboard, type “dbo”)<br>
<br>
3) Then set the breakpoint at the (*pScriptTextOut)() call here<br>
<a class="moz-txt-link-freetext" href="http://opengrok.libreoffice.org/xref/libs-gui/vcl/win/source/gdi/winlayout.cxx#2238">http://opengrok.libreoffice.org/xref/libs-gui/vcl/win/source/gdi/winlayout.cxx#2238</a>
<br>
<br>
4) Still in the Title box, type an English character “a” to make<br>
กินa<br>
The character “a” will be displayed *over* “น” which is the
characteristic of this bug. The English text run will be displayed
starting after the first non-spacing mark ( ิ )<br>
<br>
5) The breakpoint will fire. LO is about to textout the Thai run
“กิน”. Let's take note of some variables<br>
aPos.nA = 0x9c --> X<br>
aPos.nB = 0x39 --> Y<br>
(mpGlyphAdvances + nMinGlyphPos)[] = [7, 0, 7, 6] --> the
width of each character in “กินa”<br>
<br>
6) In the debugger, run to continue debugging. The breakpoint will
fire again. LO is about to textout the English run “a”. Let's look
at the variables again:-<br>
aPos.nA = 0xa3 --> X<br>
aPos.nB = 0x39 --> Y<br>
(mpGlyphAdvances + nMinGlyphPos)[] = [6] --> the width of the
character “a”<br>
<br>
Please note that the value of aPos.nA should be 0xaa (0x9c + 7 + 0
+ 7) but it is 0xa3 (0x9c + 7). It seems like that computation of
the width of the last text run is stop at the first non-spacing
character. We can repeat the same process with different text and
always reach the same conclusion. However, we can't find the code
that compute the aPos.nA before textout each run.<br>
<br>
Anyone has an idea where should I start looking?</font><br>
<div class="moz-signature">-- <br>
_/|\_ <i>Samphan Raruenrom.</i> Osdev - Open Source Development
Co., Ltd.<br>
<i>สัมพันธ์ ระรื่นรมย์.</i> โอเอสเด็บ - บริษัท
โอเพนซอร์สดิเวลอปเมนต์ จำกัด<br>
tel: +66 2 269 9889 web: <a href="http://www.osdev.co.th/">osdev.co.th</a><br>
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