template static field appearing in two different CUs

I saw some warnings and got suspicious, so I converted
the OSL_ENSURE to assert, and then found that we
have two copies of the s_nRefCount static field, which
obviously causes trouble.

I tried to fix this by removing usage of this dubious
template class, but the templates classes are intertwined,
and that lead to a very large patch with weird failures.

So this is a hacky minimal fix, using explicit template
instantiation to force the code to only be emitted
in a single library.

Change-Id: I634afb8b40570f2e7e0f8da541b8a2b6325fdc29
Reviewed-on: https://gerrit.collaboraoffice.com/c/core/+/904
Reviewed-by: Noel Grandin <noel.grandin@collabora.com>
Tested-by: Jenkins CPCI <releng@collaboraoffice.com>
(cherry picked from commit af69817a343ccf1411f6f8980c94ed1f696769b4)
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/207023
Reviewed-by: Julien Nabet <serval2412@yahoo.fr>
Tested-by: Jenkins

include/comphelper/proparrhlp.hxx

@@ -100,7 +100,7 @@ template <class TYPE>
 OPropertyArrayUsageHelper<TYPE>::~OPropertyArrayUsageHelper()
 {
     std::unique_lock aGuard(theMutex());
-    OSL_ENSURE(s_nRefCount > 0, "OPropertyArrayUsageHelper::~OPropertyArrayUsageHelper : suspicious call : have a refcount of 0 !");
+    assert(s_nRefCount > 0 && "OPropertyArrayUsageHelper::~OPropertyArrayUsageHelper : suspicious call : have a refcount of 0 !");
     if (!--s_nRefCount)
     {
         delete s_pProps;
@@ -111,12 +111,12 @@ OPropertyArrayUsageHelper<TYPE>::~OPropertyArrayUsageHelper()
 template <class TYPE>
 ::cppu::IPropertyArrayHelper* OPropertyArrayUsageHelper<TYPE>::getArrayHelper()
 {
-    OSL_ENSURE(s_nRefCount, "OPropertyArrayUsageHelper::getArrayHelper : suspicious call : have a refcount of 0 !");
     std::unique_lock aGuard(theMutex());
+    assert(s_nRefCount && "OPropertyArrayUsageHelper::getArrayHelper : suspicious call : have a refcount of 0 !");
     if (!s_pProps)
     {
         s_pProps = createArrayHelper();
-        OSL_ENSURE(s_pProps, "OPropertyArrayUsageHelper::getArrayHelper : createArrayHelper returned nonsense !");
+        assert(s_pProps && "OPropertyArrayUsageHelper::getArrayHelper : createArrayHelper returned nonsense !");
     }
     return s_pProps;
 }

include/svtools/toolboxcontroller.hxx

@@ -45,6 +45,14 @@ namespace weld { class Toolbar; }
 
 class ToolBox;
 
+namespace svt
+{
+    class ToolboxController;
+}
+
+// extern template otherwise the ref-counting magic here ends up duplicated across multiple libraries
+extern template class SAL_DLLPUBLIC_TEMPLATE comphelper::OPropertyArrayUsageHelper<svt::ToolboxController>;
+
 namespace svt
 {
 

svtools/source/uno/toolboxcontroller.cxx

@@ -48,6 +48,8 @@ using namespace css::beans;
 using namespace css::lang;
 using namespace css::frame;
 
+template class comphelper::OPropertyArrayUsageHelper<svt::ToolboxController>;
+
 namespace svt
 {