Imagecache: do not abort/crash when too many error messages are accumulated

[brechtvl]

I suspect this is not the proper solution, submitting this mostly to get advice.

I got a bug report with an OSL shader like this.

shader test(string Texture = "/some/file/that/does/not/exist.png", output color Color = 0)
{
    int resolution[2];

    if(gettextureinfo(Texture, "resolution", resolution)){
        float aspectratio = (float)resolution[1]/(float)resolution[0];
        Color = texture(Texture, P[0]*aspectratio, P[1]);
    }
}

This will call TextureSystem::get_texture_info many times, which leads to many errors reported due to the missing files, the error mesasages will exceed 16MB, and it will abort/crash. I think that there should be no crash at least, even if the user should be calling gettextureinfo(Texture, "exists", exists)?

[lgritz]

This doesn't seem like the right fix to me. I think that what this is indicating is that somewhere, we ought to be checking an error code and clearing the error message, but are not.

I'll see if I can track it down.

[lgritz]

Closing because I think that whatever was going on here has long since been fixed. With the modern OIIO & OSL code bases, this example does not accumulate error or have any other problems.