segfault in case ogre init fails

[vincele]

I got the following segfault :

Code: Select all

main() caught exception(std::runtime_error): Failed to find an Ogre GL render system.

Program received signal SIGSEGV, Segmentation fault.
Ogre::Root::uninstallPlugin (this=0x7fffe40fc8d8, plugin=0x0)
    at /build/ogre-1.8-f16G5H/ogre-1.8-1.8.0+dfsg1/OgreMain/src/OgreRoot.cpp:1304
(gdb) bt
#0  Ogre::Root::uninstallPlugin (this=0x7fffe40fc8d8, plugin=0x0)
    at /build/ogre-1.8-f16G5H/ogre-1.8-1.8.0+dfsg1/OgreMain/src/OgreRoot.cpp:1304
#1  0x0000000000df1638 in mainSetupAndRunOgre ()
    at /home/vince/repo/upstream/FreeOrion-llvm/client/human/chmain.cpp:373
#2  0x0000000000dec0c3 in main (argc=1, argv=0x7fffffffe358)
    at /home/vince/repo/upstream/FreeOrion-llvm/client/human/chmain.cpp:88

And the following patch fixes it. The code throws a runtime exception before ois_input_plugin is initialized, so we should not unregister & delete in that case...

[The extension diff has been deactivated and can no longer be displayed.]

[adrian_broher]

Shouldn't this patch be part of the sdl patch? How can I reproduce this error?

[Mitten.O]

Shouldn't this patch be part of the sdl patch?

No. The SDL patch replaces Ogre GUI. This seems to fix a corner case in Ogre GUI initialization.

If the SDL path does get adopted, this bug becomes obsolete,
there is no other connection.

[vincele]

Shouldn't this patch be part of the sdl patch? How can I reproduce this error?

No, this is current SVN code accessing uninitialized memory. I dunno how to reproduce, I was toying with an LLVM 3.6 ASAN build, and it segfaulted right at the first (an successive) run(s)...

If you follow the code in chmain.cpp int mainSetupAndRunOgre(), you'll see line 270 that in case getRenderSystemByName() is not successful, the exception throwing made the code go directly to cleanup code, which is not properly guarded against NULL pointers.

Edit: In fact, it happened because the file ogre_plugins.cfg was not present in the same directory as the freorion binary (I'm building out of source tree). So you can easily reproduce by renaming temporarily this file...

[adrian_broher]

Thanks for the patch. Commited as r7572.