nuget project fixes

issue #189 (comment)
nuget #201

projects/nuget.cmake

@@ -12,32 +12,44 @@ set(PRO_NUGET
   DLMD5 ef16c016d7eb396c8f65888a53b69d78
   )
 ########################################
+function(patch_nuget)
+  # do nothing here
+  # don't want xpPatchProject(${PRO_NUGET}) called automatically
+  # because then an ExternalProject_Add(nuget) will try to extract the executable
+  # which doesn't make any sense...
+endfunction()
+########################################
 function(build_nuget)
   if(NOT (XP_DEFAULT OR XP_PRO_NUGET))
     return()
   endif()
   if(NOT MSVC)
     return()
   endif()
-  xpDownloadProject(${PRO_NUGET}) # download_${fn} target
   xpGetArgValue(${PRO_NUGET} ARG DLURL VALUE dwnldUrl)
   get_filename_component(fn ${dwnldUrl} NAME)
+  if(NOT TARGET download_${fn})
+    xpDownloadProject(${PRO_NUGET}) # download_${fn} target
+    message(STATUS "target download_${fn}")
+  endif()
   set(tgtDep download_${fn})
   if(DEFINED XP_NUGET_COMPLETE_PKG)
     xpGetArgValue(${PRO_NUGET} ARG VER VALUE VER)
     configure_file(${PRO_DIR}/use/usexp-nuget-config.cmake ${STAGE_DIR}/share/cmake/
       @ONLY NEWLINE_STYLE LF
       )
-    ExternalProject_Add(nuget_bld DEPENDS ${tgtDep}
-      DOWNLOAD_COMMAND "" DOWNLOAD_DIR ${NULL_DIR} CONFIGURE_COMMAND ""
-      SOURCE_DIR ${NULL_DIR} BINARY_DIR ${NULL_DIR} INSTALL_DIR ${NULL_DIR}
-      BUILD_COMMAND ${CMAKE_COMMAND} -E copy_if_different ${DWNLD_DIR}/${fn} ${STAGE_DIR}/bin/${fn}
-      INSTALL_COMMAND ""
-      )
-    set_property(TARGET nuget_bld PROPERTY FOLDER ${bld_folder})
+    if(NOT TARGET nuget_bld)
+      ExternalProject_Add(nuget_bld DEPENDS ${tgtDep}
+        DOWNLOAD_COMMAND "" DOWNLOAD_DIR ${NULL_DIR} CONFIGURE_COMMAND ""
+        SOURCE_DIR ${NULL_DIR} BINARY_DIR ${NULL_DIR} INSTALL_DIR ${NULL_DIR}
+        BUILD_COMMAND ${CMAKE_COMMAND} -E copy_if_different ${DWNLD_DIR}/${fn} ${STAGE_DIR}/bin/${fn}
+        INSTALL_COMMAND ""
+        )
+      set_property(TARGET nuget_bld PROPERTY FOLDER ${bld_folder})
+      message(STATUS "target nuget_bld")
+    endif()
     set(tgtDep nuget_bld)
   endif()
-  message(STATUS "target ${tgtDep}")
   if(ARGN)
     set(${ARGN} ${tgtDep} PARENT_SCOPE)
     set(NUGET_EXE ${DWNLD_DIR}/${fn} PARENT_SCOPE)