Re: [changeset] Asian Characters and strchr()

[Ben Abbott]

On Mar 11, 2009, at 3:33 PM, Jaroslav Hajek wrote:

> On Wed, Mar 11, 2009 at 8:24 AM, Ben Abbott <address@hidden> wrote:
> > I noticed that fileparts give an error when the full-file contains  
> > asian
> > characters.
> >
> > ctave:209> fileparts ("System/Library/Fonts/junk.ttf")
> > error: subscript indices must be either positive integers or  
> > logicals.
> > error: called from:
> > error:
> > /Users/bpabbott/Development/mercurial/octave-3.1.53/scripts/strings/ 
> > strchr.m
> > at line 40, column 19
> > error:
> > /Users/bpabbott/Development/mercurial/octave-3.1.53/scripts/ 
> > miscellaneous/fileparts.m
> > at line 30, column 10
> >
> > It appears that there is a simple fix for strchr, but it will  
> > depend upon
> > the ascii equivalent for Asian fonts.
> >
> > I'm seeing negative values.
> >
> > fullfile = "System/Library/Fonts/junk.ttf";
> > octave:211> double(fullfile)
> > ans =
> >
> > Columns 1 through 16:
> >
> >   83   121   115   116   101   109    47    76   105    98   114     
> > 97
> > 114   121    47    70
> >
> > Columns 17 through 32:
> >
> >  111   110   116   115    47   -27  -115  -114   -26  -106  -121    
> > -25
> > -69  -122   -23   -69
> >
> > Columns 33 through 37:
> >
> > -111    46   116   116   102
> >
> > Can anyone tell me what the permissible range for integer values of  
> > Asian
> > characters is?
>
> I think a char->double conversion is supposed to yield nonnegative
> values, so this seems buggy.
>
> > I'm planning to patch strchr, any reason I shouldn't do that?
>
> I don't think there's a bug in strchr. This is clearly caused by the
> negative values.

For Asian fonts the values are 16bit ... unsigned or signed I don't  
know. However, it really doesn't matter in this instance. I only need  
to know how many values are part of the standard (so I don't waste  
time and memory).

For the present time, I've assumed the values for signed intergers  
range from -(2^15-1) to 2^15.

I've attached a changeset.

Ben

changeset-strchr.patch
Description: Binary data