[Zlib-devel] 1.2.5 DLL broken?

[jbowler at acm.org]

From: ctruta at gmail.com [mailto:ctruta at gmail.com] On Behalf Of Cosmin Truta
>Maybe this is a bug in MinGW, or some compatibility broken at some point in the
>Visual Studio development cycle, or both. I wouldn't mind adding a short statement
>that summarizes John's long analysis, but at this point I wouldn't know exactly what
>should I write.

The problem I saw was a C runtime library problem and it was specific to using DLL runtimes.

The use of DLL runtime results in the *name* of the DLL built in to both the applications and the DLLs.   Consequently if different C Runtime DLLs get built into different DLLs the application will end up loading two C runtimes.

The fundamental bug is that two C runtimes cannot co-exist.   This was not the case before VS2010 - I successfully ran programs that loaded two runtimes - but I think something changed.  All the same, it's a very bad idea to have two C runtimes because objects created in one will most likely be totally incompatible with the APIs for the same object in another.

John Bowler <jbowler at acm.org>