[ft-devel] Implementation Error of FreeType function FT_Get_PFR_Metrics()

[Chi Nguyen]

To freetype maintainers,

In developing the test for the freetype function FT_Get_PFR_Metrics(), we
have encountered the following implementation bugs:

1) If we make a call to FT_Get_PFR_Metrics() function with a non-pfr font
(FreeMono.ttf for example) and any of the parameters ametrics_y_scale,
ametrics_resolution, ametrics_x_scale or aoutline_resolution being NULL, a
segmentation fault will happen. The spec specified that any or all of these
parameters can be NULL.

2) If we make a call to FT_Get_PFR_Metrics() function with a non-pfr font
(FreeMono.ttf for example) and none of the parameters ametrics_y_scale,
ametrics_resolution, ametrics_x_scale or aoutline_resolution are NULL the
function returned an error code 0 (success) instead of a non-zero error code
to indicate failure.

We have tested this on 32-bit and 64-bit x86 based test systems running
under the following distros OpenSuSE 11 (32 bit), Ubuntu 8.04 (ia32), RHEL52
x86-64, SLES 10.1 (32bit), Fedora 9 (32bit) with freetype 2.1.10 and
freetype 2.3.7. The non-pfr fonts that we used to verify this claim included
'FreeMono.ttf', 'pala.ttf', 'BSSYM7.TTF' and 'n019043l.pfb'

Included with this email is a c program ft_get_pfr_metrics.c to help
demonstrate these two bugs.

To reproduce the first bug, use "ft_get_pfr_metrics <font_file_name> a b c
d"   where at least one or all of {a, b, c, d} is/are 0.

To reproduce the second bug, use "ft_get_pfr_metrics <font_file_name> 1 1 1
1" for example.

The specified <font_file_name> should exist in the local directory ./fonts.

Also included with this email is a snippet of a source code implementation
of the function FT_Get_PFR_Metrics() that we were able to look-up.

Thank you very much for your time and please let us know any ruling/finding
that you may have.


Sincerely yours,


Nguyen Trung Chi

NEC Solutions VietNam

Get_PFR_Metrics.rar
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