[haiku-bugs] Re: [Haiku] #8447: TextView GetText() doesn't straddle the "Gap" properly
- From: "Pete" <trac@xxxxxxxxxxxx>
- Date: Fri, 19 Sep 2014 06:46:43 -0000
#8447: TextView GetText() doesn't straddle the "Gap" properly
----------------------------------+----------------------------
Reporter: Pete | Owner: axeld
Type: bug | Status: new
Priority: critical | Milestone: R1/alpha5
Component: Kits/Interface Kit | Version: R1/Development
Resolution: | Keywords:
Blocked By: | Blocking: 11132
Has a Patch: 1 | Platform: All
----------------------------------+----------------------------
Comment (by Pete):
Replying to [comment:9 jackburton]:
> It's been a while since I last touched that code, but it seems to me
that "offset" should be added to the second parameter of the second call
to memcpy(), like we do for the first.
> IOW:
> {{{
> memcpy(buffer, fBuffer + offset, beforeLen);
> memcpy(buffer + beforeLen, fBuffer + fGapIndex + fGapCount + offset,
afterLen);
> }}}
>
> Otherwise the code wouldn't work with offset != 0.
No, because the offset is irrelevant for the second memcpy. The first one
copies the segment of text from offset up to the gap (pointed to by
fGapIndex); beforelen is calculated to do this. The second memcpy has to
start ''immediately'' after the gap, which is pointed to by fGapIndex +
fGapCount. Adding in offset as well would push things too far down.
FTR I ran a check earlier on a patched libbe.so, using Weaver and two
connected StreamView elements. (That was where I noticed the problem in
the first place, as it uses BTextView's 'GetText'.)
I ran extensive edits in one StreamView -- including UTF-8 characters --
and transmitted arbitrary clips to the other. Seemed flawless under all
conditions.
--
Ticket URL: <https://dev.haiku-os.org/ticket/8447#comment:10>
Haiku <https://dev.haiku-os.org>
Haiku - the operating system.
Other related posts:
