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[devel] Improved gamma range checks and other things OpenWatcom warns about.

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This commit is contained in:
John Bowler
2011-06-11 06:42:06 -05:00
committed by Glenn Randers-Pehrson
parent b011fe1c12
commit d2f0bc2d13
5 changed files with 28 additions and 30 deletions
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21
pngset.c
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@@ -94,15 +94,16 @@ png_set_gAMA_fixed(png_structp png_ptr, png_infop info_ptr, png_fixed_point
if (png_ptr == NULL || info_ptr == NULL)
return;
/* Previously these values were limited, however they must be
* wrong, therefore storing them (and setting PNG_INFO_gAMA)
* must be wrong too.
/* Changed in libpng-1.5.4 to limit the values to ensure overflow can't
* occur. Since the fixed point representation is assymetrical it is
* possible for 1/gamma to overflow the limit of 21474 and this means the
* gamma value must be at least 5/100000 and hence at most 20000.0. For
* safety the limits here are a little narrower. The values are 0.00016 to
* 6250.0, which are truely ridiculous gammma values (and will produce
* displays that are all black or all white.)
*/
if (file_gamma > (png_fixed_point)PNG_UINT_31_MAX)
png_warning(png_ptr, "Gamma too large, ignored");
else if (file_gamma <= 0)
png_warning(png_ptr, "Negative or zero gamma ignored");
if (file_gamma < 16 || file_gamma > 625000000)
png_warning(png_ptr, "Out of range gamma value ignored");
else
{
@@ -340,11 +341,11 @@ png_set_sCAL_s(png_structp png_ptr, png_infop info_ptr,
if (unit != 1 && unit != 2)
png_error(png_ptr, "Invalid sCAL unit");
if (swidth == NULL || (lengthw = png_strlen(swidth)) <= 0 ||
if (swidth == NULL || (lengthw = png_strlen(swidth)) == 0 ||
swidth[0] == 45 /* '-' */ || !png_check_fp_string(swidth, lengthw))
png_error(png_ptr, "Invalid sCAL width");
if (sheight == NULL || (lengthh = png_strlen(sheight)) <= 0 ||
if (sheight == NULL || (lengthh = png_strlen(sheight)) == 0 ||
sheight[0] == 45 /* '-' */ || !png_check_fp_string(sheight, lengthh))
png_error(png_ptr, "Invalid sCAL height");