[Scummvm-tracker] [ScummVM :: Bugs] #14872: GRAPHICS: HQScaler crash when exiting Indy3-Mac in HQ3X

[ScummVM :: Bugs]

#14872: GRAPHICS: HQScaler crash when exiting Indy3-Mac in HQ3X
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Reporter:  dwatteau  |       Owner:  (none)
    Type:  defect    |      Status:  new
Priority:  normal    |   Component:  Graphics: Scalers
 Version:            |  Resolution:
Keywords:            |        Game:  Indiana Jones 3
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Comment (by eriktorbjorn):

 Well, something's odd about the HQ3x scaler or, more likely, the way it's
 used here. When it gets to the end of the HQ3x_implementation() function,
 it does this:

 {{{
 p += nextlineSrc - width;
 q += (nextlineDst - width) * 3;
 }}}

 At this point, width is 16, nextlineSrc is 6, and nextlineDst is 12. And I
 think that through the wonders of signed math, adding "nextlineSrc -
 width" is not the same as first adding nextlineSrc and then subtracting
 width, because the value of p increases by a lot.

 Breaking it up like that isn't the solution to the problem, though it does
 make the code run for a bit longer before it crashes. But perhaps it is a
 clue?
-- 
Ticket URL: <https://bugs.scummvm.org/ticket/14872#comment:5>
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