[Sofa.Helper] PluginManager: check if a plugin is already loaded with a different path

[fredroy]

The case arises mostly because of running runSofa from a build directory but you set SOFA_ROOT. It will then tried to load plugins from the install afterwards, etc..., leading to stuff like:

[WARNING] [ObjectFactory] Default template for class DynamicSparseGridGeometryAlgorithms already registered (Vec3d), do not register Vec3d as the default
[WARNING] [ObjectFactory] Class already registered: DynamicSparseGridGeometryAlgorithms<Vec2d>
[WARNING] [ObjectFactory] Class already registered: DynamicSparseGridGeometryAlgorithms<Vec3d>
....

or with a cryptic error message if you try to use the PluginManager from the GUI:

[INFO]    [PluginManager] Plugin not found in loaded plugins: ..../bin/RelWithDebInfo/SofaNonUniformFem.dll
[ERROR]   [SofaPluginManager] plugin should be loaded: ..../bin/RelWithDebInfo/SofaNonUniformFem.dll

Now, if you try to load twice the plugins (from differents paths then), it will print:
(one dll is in build/bin/Release/ and the other one directly in build/

[WARNING] [PluginManager] This plugin SofaNonUniformFem has been loaded from a different path, it will certainly lead to bugs or crashes...
You tried to load: ....build/bin/Release/SofaNonUniformFem.dll
Already loaded: ....\build\SofaNonUniformFem.dll
[WARNING] [PluginManager] Plugin SofaNonUniformFem is already loaded from a different path, check you configuration.

The "double information" comes from the fact that in the end we consider the plugin as loaded ; the code afterwards will try to load the plugin nevertheless (hence having to detect twice the duplication)
In the GUI code for example:

sofa/modules/SofaGuiQt/src/sofa/gui/qt/SofaPluginManager.cpp

Line 120 in 7169130

if(sofa::helper::system::PluginManager::getInstance().loadPluginByPath(pluginFile,&sstream))

Obviously it is really not advised to continue to use Sofa if this case occurs but at least the user will know what is going on.

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[alxbilger]

It will probably help to diagnose this issue #2338

[epernod]

"déjà vu", no ?
#1472

[fredroy]

"déjà vu", no ?
#1472

I suppose #1472 was not working then 😬