Rendering raster fonts with AGG may cause crash in mapserver

[tamas]

I've noticed that rendering raster fonts when the character code falls outside of the 23-127 domain may cause crash in mapserver. The following patch provides a fix for the problem, however I consider this as rather a bug in the AGG libraries

[dmorissette]

The following problem description (from Tamas on mapserver-dev) should be reported to the AGG project if/when there is a new maintainer:

There is a signed char to unsigned int
conversion in the agg renderer code which causes that the negative
character codes are converted to large integer numbers.  Then this
number is blindly used as an index to access the pixel information of
the corresponding character in the array specified in
agg_embedded_raster_fonts.cpp.
See also "render_text' in agg_renderer_raster_text.h line 51 and
'prepare' in agg_glyph_raster_bin.h line 82

I consider this as a deficiency of the agg library itself but I'm not
too keen to prepare fixes for AGG at the moment. (I'm using AGG 2.4
right now)

[tamas]

Applied the modified fix in r7858

[tamas]

Committed the fix to branch 5-2 in r7860