Patch to fix incorrect mbstring usage

[liels_bugs]

First of all, thanks for the great product! Hopefully
my patch will help to make it more suitable for
non-english people too.

* * *

program/include/main.inc contains two errors in
mbstring usage. These errors prevent mbstring from
using on non-english languages and cause empty body for
messages with non-english character sets (like koi8-r
or windows-1257).

Firsts, this file determines if mbstring can be used at
all and it does it by calling mb_language. This is
wrong because this function is not right for this task.
Suppose your display language is Latvian (mb_language
returns false for "lv"). You get e-mail with Norwegian
letters and charset. Now you are going to convert it to
utf-8 but you cannot do it because you just disabled
mbstring! And you did it by checking the language code
that has nothing to do with incoming mail or display
encoding. These are completely unrelated things!

Second, code incorrectly works with
mb_convert_encoding. It tries to check if encoding is
directly supported by comparing it to arrays. This will
work in some cases but not in all. Your code depends on
the existance of mb_string_encodings, which is not
always present. Thus you leave many charsets out. In
fact, most of them for all PHP4 versions. Instead you
should call mb_convert_encoding and compare result to
empty string (read manual!). This is the only right way.

I attach the patch that fixes mb_string usage and makes
proper conversion. I did not look to anything else in
the file, just fixed mbstring issues. Patch is verified
on my test server.

You make a great product - fast, nice looking and very
promising. Hope you will succeed. I started to play
with it 2 hours ago and already became a big fan :)
Very, very good!

[xpnet]

Where can I download patch?

[ericliang]

Please upload your patch in order for the rest of us to check your changes since we have similar issues with conversion of data in other languages.

[thomasb]

Patch for the 0.1-beta2 version of program/include/main.inc

[thomasb]

Applied to trunk