riched20: do not return incorrect values from ME_CharFromPoint[Cursor]

[Thomas Faber]

Hey,

On 2011-10-24 20:03, Alexandre Julliard wrote:
> Thomas Faber <thfabba at gmx.de> writes:
> 
>> Windows's version of GetTextExtentExPointW, which is called in that function,
>> returns a value of 1 in this case (Wine's does not, which would appear to be
>> a bug), leading to the "i<len" assertion failure if there is no text in the
>> control.
>> The patch fixes riched20 to correctly handle either behavior by
>> adding a fast path for cx <= 0 (the function obviously needs to return 0 in
>> the cx == 0 case too, so it can skip the calculation).
> 
> You should not be adding workarounds for Wine bugs, the bugs need to be
> fixed instead.
> 

it is not a workaround. It is the current riched20 code that relies on the bug
being present (hence why it asserts on Windows).
The patch makes it work with a _correctly working_ version of
GetTextExtentExPointW (and also with the current one).
You could see it as a prerequisite to fixing that bug (that is, to fixing it
without breaking richedit controls).

Regards,
Tom