Crash when displaying savegame list
Posted: Thu Apr 11, 2019 1:45 pm
We have updated The Forestale to GZDoom 3.7.2 and got a crash when displaying the savegame list. It was traced to the following code:
PNGTexture_CreateFromFile:
FSavegameManager::ExtractSaveData:
The problem is that if any of the paramaters in if (compression != 0 || filter != 0 || interlace > 0 || bitdepth != 8 || (colortype != 2 && colortype != 3)) is incorrect, PNGTexture_CreateFromFile returns a null pointer and FSavegameManager::ExtractSaveData accesses it. One of the savegames had a wrong colortype, presumably because it was saved without a screenshot. Even if it got a bad colortype for a different reason, that's no reason to crash instead of ignoring the file.
PNGTexture_CreateFromFile:
Code: Select all
// Reject anything that cannot be put into a savegame picture by GZDoom itself.
if (compression != 0 || filter != 0 || interlace > 0 || bitdepth != 8 || (colortype != 2 && colortype != 3)) return nullptr;
else return new FPNGFileTexture (png->File, width, height, colortype);
Code: Select all
PNGHandle *png = M_VerifyPNG(picreader);
if (png != nullptr)
{
SavePic = PNGTexture_CreateFromFile(png, node->Filename);
delete png;
if (SavePic->GetDisplayWidth() == 1 && SavePic->GetDisplayHeight() == 1)