[sword-devel] Crash when getting module type

[Donna Whisnant]

David,

Based on the code you are showing, I can pretty much guarantee you that your segfault is caused by tempMod being a null pointer -- i.e. that the value of the map element you are iterating is null.

Your code needs to be more defensive and check if tempMod is a nullptr before dereferencing it.  Adding an 'if' around that code block should fix your segfault problem.  But you'll have to determine why some module entries in your map are nulls -- perhaps you missed loading modules or something?  Your code snippet doesn't show any of those details...  it only shows iterating something that appears to be a std::map.

Donna


> Date: Tue, 24 Oct 2023 16:04:03 -0400
> From: "David \"Judah's Shadow\" Blue"
> Subject: [sword-devel] Crash when getting module type
> Message-ID: <5986010.lOV4Wx5bFT at brooks>
> Content-Type: text/plain; charset="us-ascii"
>
> I've resumed working on bibish some, and I'm getting a weird crash I never had
> before. I'm trying to interate through the list of installed modules and
> select those that match a given type. This is my code:
>
>
>     for(libraryIterator = swordLibrary.Modules.begin();
>         libraryIterator != swordLibrary.Modules.end();
>         libraryIterator++) {
>
>
>         sword::SWModule *tempMod = libraryIterator->second;
>         modType = tempMod->getType();
>
>         if(modType == selectedType) {
>             module = "For ";
>             module += tempMod->getDescription();
>             module += " select ";
>             module += tempMod->getName();
>             moduleList.push_front(module);
>             module = "";
>         }
>     }
>
> I am getting a segfault on the modType = tempMod->getType(); line.  I'm 
> using
> 1.9.0 built myself. I'm not sure what I'm doing wrong.