WiX Heat.exe generates different output after VS2008 -> VS2015 upgrade - c++

Question

We execute the following command line with heat (3.0.5210.0):
heat.exe -srd -suid file OurLib.dll -out bin_OurLib.tmp
OurLib.dll is a VC++ 2008 dll file, it's a COM component.
Output (bin_OurLib.tmp)
<?xml version="1.0" encoding="utf-8"?>
<Wix xmlns="http://schemas.microsoft.com/wix/2006/wi">
<Fragment>
<DirectoryRef Id="TARGETDIR">
<Component Id="OurLib.dll" Guid="PUT-GUID-HERE">
<File Id="OurLib.dll" KeyPath="yes" Source="SourceDir\OurLib.dll">
<Class Id="{B1AB297C-1BC6-65E1-A7C1-A1833DFAED6A}" Context="InprocServer32" Description="OurProduct.OurLib">
<ProgId Id="OurProduct.OurLib" Description="OurProduct.OurLib" />
</Class>
</File>
</Component>
</DirectoryRef>
</Fragment>
</Wix>
This works fine.
Now we updated the VS to 2015, and compiled OurLib with it.
Running the same heat command now results in different output:
<?xml version="1.0" encoding="utf-8"?>
<Wix xmlns="http://schemas.microsoft.com/wix/2006/wi">
<Fragment>
<DirectoryRef Id="TARGETDIR">
<Component Id="OurLib.dll" Guid="PUT-GUID-HERE">
<Class Id="{B1AB297C-1BC6-65E1-A7C1-A1833DFAED6A}" Context="InprocServer32" Description="OurProduct.OurLib">
<ProgId Id="OurProduct.OurLib" Description="OurProduct.OurLib" />
</Class>
<File Id="OurLib.dll" KeyPath="yes" Source="SourceDir\OurLib.dll" />
<RegistryValue Root="HKCR" Key="CLSID\{B1AB297C-1BC6-65E1-A7C1-A1833DFAED6A}\InProcServer32" Value=""[#OurLib.dll]"" Type="string" Action="write" />
</Component>
</DirectoryRef>
</Fragment>
</Wix>
And when wix is linking, it gives error:
error LGHT0130 : The primary key 'reg51A1FC16367511AF81E9B18CA009A1C6' is duplicated in table 'Registry'. Please remove one of the entries or rename a part of the primary key to avoid the collision.
Checking the wixobj file, reg51A1FC16367511AF81E9B18CA009A1C6 is related to line
<Class Id="{B1AB297C-1BC6-65E1-A7C1-A1833DFAED6A}...." and <RegistryValue Root="HKCR" Key="CLSID\{B1AB.... - obviously.
Anwyay, this is obviously due to the generated wix output files are different.
Why is that if compiling a dll with a newer C++ compiler will cause WIX HEAT to generate different output, while running the same options, etc.
And how can I have back the same "old" output, which we need.
Tried with -scom and -sreg, none of them gave back the "old" output.

Answer 1

Well primary key duplicated means you've got that same RegistryValue in two different places in your wix source code somehow.
Or maybe the newer DLL is self-registering differently? It's putting the InProcServer32 value in quotes. I don't think that's normal.
Or have you checked that your 2008 and 2015 DLL source and project files are identical? The VS project upgrade process changes things...