modules: different search order for plugin libs in FindMagnum.

This makes Vcpkg-built static plugins be found correctly. Previously
both the debug and release variant pointed to the same lib.

doc/changelog.dox

@@ -280,6 +280,8 @@ See also:
     [OpenGL_GL_PREFERENCE](https://cmake.org/cmake/help/v3.11/module/FindOpenGL.html#linux-specific)
     from outside on systems where GLVND doesn't work properly (before the build
     scripts and `FindMagnum.cmake` always forced GLVND)
+-   `FindMagnum.cmake` now correctly finds debug versions of statically built
+    plugins when using Vcpkg
 
 @subsection changelog-latest-bugfixes Bug fixes
 

modules/FindMagnum.cmake

@@ -550,11 +550,17 @@ foreach(_component ${Magnum_FIND_COMPONENTS})
             set(CMAKE_FIND_LIBRARY_PREFIXES "${CMAKE_FIND_LIBRARY_PREFIXES};")
 
             # Try to find both debug and release version. Dynamic and static
-            # debug libraries are in different places.
+            # debug libraries are in different places. Static debug plugins are
-            find_library(MAGNUM_${_COMPONENT}_LIBRARY_DEBUG ${_component}
+            # in magnum/ with a -d suffix while dynamic debug plugins are in
-                PATH_SUFFIXES magnum-d/${_MAGNUM_${_COMPONENT}_PATH_SUFFIX})
+            # magnum-d/ with no suffix. Problem is that Vcpkg's library linking
+            # automagic needs the static libs to be in the root library
+            # directory along with everything else and so we need to search for
+            # the -d suffixed version *before* the unsuffixed so it doesn't
+            # pick the release library for both debug and release.
             find_library(MAGNUM_${_COMPONENT}_LIBRARY_DEBUG ${_component}-d
                 PATH_SUFFIXES magnum/${_MAGNUM_${_COMPONENT}_PATH_SUFFIX})
+            find_library(MAGNUM_${_COMPONENT}_LIBRARY_DEBUG ${_component}
+                PATH_SUFFIXES magnum-d/${_MAGNUM_${_COMPONENT}_PATH_SUFFIX})
             find_library(MAGNUM_${_COMPONENT}_LIBRARY_RELEASE ${_component}
                 PATH_SUFFIXES magnum/${_MAGNUM_${_COMPONENT}_PATH_SUFFIX})
             mark_as_advanced(MAGNUM_${_COMPONENT}_LIBRARY_DEBUG