From:             ken at sonicwizardry dot com
Operating system: Linux
PHP version:      5.0.0RC2
PHP Bug Type:     GD related
Bug description:  ImageFilter, no bounds check processing image per-pixel: creates a 
black border

Description:
------------
Running ImageFilter on an image creates a black border around the edge
because it references non-existing pixels off of the image (beyond image
size).  Bounds check/clamp added to convolution loop.  Code DIFF is
below:

File path: ext/gd/libgd/gd.c

3607,3610c3607,3614 

< pxl = f(srcback, x-(3>>1)+i, y-(3>>1)+j); 
< new_r += (float)gdImageRed(srcback, pxl) * filter[j][i]; 
< new_g += (float)gdImageGreen(srcback, pxl) * filter[j][i]; 
< new_b += (float)gdImageBlue(srcback, pxl) * filter[j][i]; 
 
--- 

> int ix = x-(3>>1)+i; 
> int iy = y-(3>>1)+j; 
> ix = (ix>=src->sx)?src->sx-1 : ((ix<0)?0:ix); 
> iy = (iy>=src->sy)?src->sy-1 : ((iy<0)?0:iy); 
> pxl = f(srcback, ix, iy); 
> new_r += (float)gdImageRed(srcback, pxl) * filter[j][i]; 
> new_g += (float)gdImageGreen(srcback, pxl) * filter[j][i]; 
> new_b += (float)gdImageBlue(srcback, pxl) * filter[j][i];


Hope this helps!
-Ken Post Jr.


-- 
Edit bug report at http://bugs.php.net/?id=28304&edit=1
-- 
Try a CVS snapshot (php4):  http://bugs.php.net/fix.php?id=28304&r=trysnapshot4
Try a CVS snapshot (php5):  http://bugs.php.net/fix.php?id=28304&r=trysnapshot5
Fixed in CVS:               http://bugs.php.net/fix.php?id=28304&r=fixedcvs
Fixed in release:           http://bugs.php.net/fix.php?id=28304&r=alreadyfixed
Need backtrace:             http://bugs.php.net/fix.php?id=28304&r=needtrace
Need Reproduce Script:      http://bugs.php.net/fix.php?id=28304&r=needscript
Try newer version:          http://bugs.php.net/fix.php?id=28304&r=oldversion
Not developer issue:        http://bugs.php.net/fix.php?id=28304&r=support
Expected behavior:          http://bugs.php.net/fix.php?id=28304&r=notwrong
Not enough info:            http://bugs.php.net/fix.php?id=28304&r=notenoughinfo
Submitted twice:            http://bugs.php.net/fix.php?id=28304&r=submittedtwice
register_globals:           http://bugs.php.net/fix.php?id=28304&r=globals
PHP 3 support discontinued: http://bugs.php.net/fix.php?id=28304&r=php3
Daylight Savings:           http://bugs.php.net/fix.php?id=28304&r=dst
IIS Stability:              http://bugs.php.net/fix.php?id=28304&r=isapi
Install GNU Sed:            http://bugs.php.net/fix.php?id=28304&r=gnused
Floating point limitations: http://bugs.php.net/fix.php?id=28304&r=float

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