bug#21260: 23.2; Devanagari windows 10

[Eli Zaretskii <eliz@gnu.org>]

[Please keep the bug address on the CC list.]

> Date: Sun, 16 Aug 2015 16:21:53 -0400
> From: Jim Funderburk <funderburk1@verizon.net>
> 
>    1.  When I open emacs 'normally'  (c:\emacs-23.2\bin\emacs.exe), type 
> some text (in *scratch* buffer)
>          'blah blah', and position the insertion point at the first 'a', 
> and then type "C-u C-x =",
>          here's what shows in the *Help* buffer:
>          character: a (97, #o141, #x61)
> preferred charset: ascii (ASCII (ISO646 IRV))
>         code point: 0x61
>             syntax: w     which means: word
>           category: .:Base, a:ASCII, l:Latin, r:Roman
>        buffer code: #x61
>          file code: #x61 (encoded by coding system iso-latin-1-dos)
>            display: by this font (glyph code)
>      uniscribe:-outline-Courier New-normal-normal-normal-mono-13-*-*-*-c-*-iso8859-1 (#x44)

OK, so Emacs does try to use Uniscribe on that system.

> 2.  Regarding usp10.dll -  I searched for it in the c:\Windows 
> directory, and found it in 4 places.
>       One of those was in System32 folder.  I copied usp10.dll to the 
> c:\emacs-23.2\bin folder, where emacs.exe resides.

The one in System32 is the wrong one: it's a 64-bit DLL, whereas Emacs
is a 32-bit executable, it should use the one in C:/Windows/SysWOW64
instead.  Please remove the DLL you put near emacs.exe, as it could
get in the way as we continue digging into this problem.

Can you show the full list of all the different usp10.dll files you
have there, including their size and time stamp?  Also, could you
please use some program like Process Explorer (from SysInternals) to
find out which one of these DLLs Emacs actually loads?

Next, there's the question with the fonts you have there.  On Windows
XP and Windows 7, Emacs uses the Mangal font to display the Hindi
script; on Windows 8.1 it uses Kokila instead.  Do you have any of
these fonts on your system?  If so, could you please show the OpenType
properties of these fonts, in particular the scripts they support and
the features they support for each script?  One program that can show
this information is FontTesterPlus, which you should be able to
download and install (I have version 1.4).

I'm sorry to ask you to do all this, but I have no access to Windows
10, and I see no such problems on all other versions through 8.1.

> 2a. In the "C-U C-X =" output of (1) above,  the presence of 'uniscribe' 
> makes me think that usp10.dll is being used already,

Yes, it is.

>            display: no font available
> 
> Character code properties: customize what to show
>    name: DEVANAGARI DOUBLE DANDA
>    general-category: Po (Punctuation, Other)
> 
> NOTE: It seems to be analyzing the character properly ---- But  I wonder 
> why it shows 'display: no font available'.

That's the crux of your problem: for some reason, Emacs rejects all
the fonts you have that are capable of supporting Devanagari.  I'm
trying to figure out why.