Re: [Patch] expand,unexpand multibyte support

[Ondrej Oprala]

On 02/20/2013 12:21 AM, Bernhard Voelker wrote:
> On 02/18/2013 04:30 PM, Ondrej Oprala wrote:
> > Hi, I've been working on multibyte support for the {un,}expand utilities
> > lately, my approach being similar to Padraig's from 2010 (
> > http://lists.gnu.org/archive/html/coreutils/2010-09/msg00029.html ) .
> > Both tools now read by lines, not bytes, and then iterate over the
> > characters properly.
> Thanks - the package maintainer of all distributions will be very happy
> once multi-byte support is integrated to all upstream coreutils programs.
>
> I can't tell too much about your patch yet - I even tried to avoid
> the umlaut-ö in my own name whenever possible my whole life ;-)
> So here are only a few general notes.
>
> I had a bit problems to compile because expand-core.h needs the types
> uintmax_t, uint32_t and uint8_t which are not yet defined.
> Moving the #include down (in src/{expand,expand-core,unexpand}.c)
> worked around this problem, e.g. expand.c:
>
> --- a/src/expand.c
> +++ b/src/expand.c
> @@ -46,13 +46,13 @@
>   # include <unistring/localcharset.h>
>   #endif
>
> -#include "expand-core.h"
> -
>   #include "system.h"
>   #include "error.h"
>   #include "fadvise.h"
>   #include "xstrndup.h"
>
> +#include "expand-core.h"
> +
>   /* The official name of this program (e.g., no 'g' prefix).  */
>   #define PROGRAM_NAME "expand"
>
>
> In the expand() and unexpand() functions, the variable rawline can
> be changed from char** to char*. This makes the code better readable.
> I'm not sure whether we should free the rawline buffer on any input
> line anyway, because it's filled by getline() and resized as needed;
> i.e. reusing malloc'ed space is not a bad thing.
>
> And instead of strdup() without checking, we should use xstrdup():
>         {
> -        line = (uint8_t *) strdup (*rawline);
> +        line = (uint8_t *) xstrdup (rawline);
>           clen = 1;
>         }
> Hopefully, we can avoid that strdup in the final version, and just
> use the buffer we already have.
>
> In the tests, please check the exit status of expand/unexpand,
> and use our own compare function; e.g. tests/expand/mb.sh:
>
> -expand < in > out
> -cmp out exp > /dev/null 2>&1 || fail=1
> +expand < in > out || fail=1
> +compare exp out || fail=1
>
> It would be good to have much more tests. I have the feeling
> that the coverage rate of expand/unexpand wasn't too great
> also in the existing tests - though the unexpand test looks
> slightly better than the expand test.
>
> Have a nice day,
> Berny
Thank you both very much for looking at the patch,
I realize the patch is a bit big and thus hard to review (for which I'm 
sorry), but
with {un,}expand tools being so tightly coupled together, I can't 
imagine a different approach.

I've made some fixes/additions.
The patch now correctly handles characters with a display length > 1,
The columns variable is now incremented by character unit length, not by 
1 implicitly.
Unexpand now uses the buffer line + offset to output pending characters 
as well,
which makes it easier to work with blanks such as ideo-space in the 
pending buffer.
(special case when pending blanks with display length == 2 get into
the pending_blank[] buffer is covered in tests.)
Speaking of tests, I've added a few test cases (thank you again for the 
ideo-space
reproducers ;) ).
Tests now use the correct compare, header files are ordered properly and 
s/strdup/xstrdup/ in code.

Thanks,
Ondrej

DIFF
Description: Text document