Merge 4ff53cf69f into 1f8b4a7f1a

include/pybind11/detail/internals.h

@@ -311,12 +311,16 @@ struct type_info {
 #endif
 
 /// On Linux/OSX, changes in __GXX_ABI_VERSION__ indicate ABI incompatibility.
-/// On MSVC, changes in _MSC_VER may indicate ABI incompatibility (#2898).
+/// On MSVC, mixing /MT and /MD will result in crashes. See (#4953)
 #ifndef PYBIND11_BUILD_ABI
 #    if defined(__GXX_ABI_VERSION)
 #        define PYBIND11_BUILD_ABI "_cxxabi" PYBIND11_TOSTRING(__GXX_ABI_VERSION)
-#    elif defined(_MSC_VER)
-#        define PYBIND11_BUILD_ABI "_mscver" PYBIND11_TOSTRING(_MSC_VER)
+#    elif defined(_MSC_VER) && defined(_MT)
+#        define PYBIND11_BUILD_ABI "_mt_mscver" PYBIND11_TOSTRING(_MSC_VER)
+#    elif defined(_MSC_VER) && defined(_MD) && (_MSC_VER >= 1900) && (_MSC_VER < 2000)
+#        define PYBIND11_BUILD_ABI "_md_mscver14"
+#    elif defined(_MSC_VER) && defined(_MD)
+#        define PYBIND11_BUILD_ABI "_md_mscver" PYBIND11_TOSTRING(_MSC_VER)
 #    else
 #        define PYBIND11_BUILD_ABI ""
 #    endif

tools/pybind11NewTools.cmake

@@ -274,10 +274,6 @@ function(pybind11_add_module target_name)
     target_link_libraries(${target_name} PRIVATE pybind11::embed)
   endif()
 
-  if(MSVC)
-    target_link_libraries(${target_name} PRIVATE pybind11::windows_extras)
-  endif()
-
   # -fvisibility=hidden is required to allow multiple modules compiled against
   # different pybind versions to work properly, and for some features (e.g.
   # py::module_local).  We force it on everything inside the `pybind11`