Dragging in preview with white background causes crash

[Gary Swofford]

This is with version 1.3. If you set a white background, bring up the preview (Ctrl-P) and try to drag the image around it will crash. It also crashes with other colors but not as consistently as white. Dragging before the preview render finishes also causes a crash, but is only consistent using white. A black background doesn't seem to cause any problems anywhere.

I've tried this only on linux but I get identical results on these dists: Ubuntu and Fedora 32-bit, Ubuntu 64-bit
Also I tried my packaged versions versus straight from source. No difference.

Here is the error reported by fr0st on Ubuntu 32-bit:

Error:
Traceback (most recent call last):
  File "/usr/share/fr0st/fr0stlib/gui/preview.py", line 229, in OnIdle
    self.Move(diff)
  File "/usr/share/fr0st/fr0stlib/gui/preview.py", line 343, in Move
    self.MoveAndZoom()
  File "/usr/share/fr0st/fr0stlib/gui/preview.py", line 371, in MoveAndZoom
    newimg = self.NewEmptyImage(fw, fh)
  File "/usr/share/fr0st/fr0stlib/gui/preview.py", line 336, in NewEmptyImage
    newimg.SetRGBRect((0 ,0, w, h), *bgcolor)
  File "/usr/lib/python2.6/dist-packages/wx-2.8-gtk2-unicode/wx/_core.py", line 2781, in SetRGBRect
    return _core_.Image_SetRGBRect(*args, **kwargs)
OverflowError: in method 'Image_SetRGBRect', expected argument 3 of type 'byte'

Platform: linux2

Config:
{'Bits': 0,
 'Edit-Post-Xform': False,
 'Favorite-Scripts': [u'/home/gary/.fr0st/scripts/reframe.py',
                      u'/home/gary/.fr0st/scripts/calculate_colors.py',
                      u'/home/gary/.fr0st/scripts/bilateral_symmetry.py',
                      u'/home/gary/.fr0st/scripts/xform_heat_map.py',
                      'None',
                      'None',
                      'None',
                      'None',
                      'None',
                      'None',
                      'None',
                      'None'],
 'Gradient-Settings': {'hue': (0.0, 1.0),
                       'nodes': (6, 12),
                       'saturation': (0.25, 1.0),
                       'value': (0.25, 1.0)},
 'Img-Dir': u'/home/gary/.fr0st/renders',
 'Img-Type': u'.png',
 'Large-Preview-Settings': {'estimator': 0,
                            'filter_radius': 0.25,
                            'quality': 10,
                            'spatial_oversample': 1},
 'Lock-Axes': True,
 'Preview-Settings': {'estimator': 0, 'filter_radius': 0, 'quality': 5},
 'Recent-Flames': (u'/home/gary/.fr0st/parameters/gary.flame',
                   u'/home/gary/.fr0st/parameters/Valflames_03.flame',
                   u'/home/gary/.fr0st/parameters/Valflames_02.flame',
                   u'/home/gary/.fr0st/parameters/Valflames.flame'),
 'Recent-Scripts': (u'/home/gary/.fr0st/scripts/default.py',),
 'Rect-Editor': ((0, 26, 865, 500), False),
 'Rect-Main': ((0, 26, 842, 689), True),
 'Rect-Preview': ((0, 0, 1208, 977), False),
 'Render-Settings': {'buffer_depth': 33,
                     'earlyclip': True,
                     'estimator': 9.0,
                     'estimator_curve': 0.40000000000000002,
                     'estimator_minimum': 0.0,
                     'filter_kernel': 6,
                     'filter_radius': 0.80000000000000004,
                     'nthreads': 0,
                     'quality': 2000,
                     'spatial_oversample': 4,
                     'transparent': 0},
 'Var-Preview-Settings': {'depth': 1, 'numvals': 20, 'range': 2},
 'Variation-Preview': True,
 'World-Pivot': False,
 'Xform-Combo': {'rotate': 15.0,
                 'scale': 1.25,
                 'translate': 0.10000000000000001},
 'flamepath': u'/home/gary/.fr0st/parameters/gary.flame',
 'jpg-quality': 95,
 'renderer': 'flam3',
 'version': 'Fr0st 1.3'}

Flame Path:
'<not set>'

UserParametersDir: /home/gary/.fr0st/parameters
RendersDir: /home/gary/.fr0st/renders
UserScriptsDir: /home/gary/.fr0st/scripts
ConfigDir: /home/gary/.fr0st
Frozen: False
AppBaseDir: /usr/bin
IconsDir: /usr/share/fr0st/icons

[Vitor Bosshard (algorias)]

yeah so it turns out the code was trying to set byte values to 256 when the bg was pure white. Not good xD