Merge pull request #1769 from dakotahawkins/fix-1764_CMake-errors-in-googlemock

Use `$<INSTALL_PREFIX>` in `target_include_directories`
diff --git a/googlemock/CMakeLists.txt b/googlemock/CMakeLists.txt
index 195d254..8a8de1f 100644
--- a/googlemock/CMakeLists.txt
+++ b/googlemock/CMakeLists.txt
@@ -118,10 +118,10 @@
 if (DEFINED CMAKE_VERSION AND NOT "${CMAKE_VERSION}" VERSION_LESS "2.8.11")
   target_include_directories(gmock SYSTEM INTERFACE
     "$<BUILD_INTERFACE:${gmock_build_include_dirs}>"
-    $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>)
+    "$<INSTALL_INTERFACE:$<INSTALL_PREFIX>/${CMAKE_INSTALL_INCLUDEDIR}>")
   target_include_directories(gmock_main SYSTEM INTERFACE
     "$<BUILD_INTERFACE:${gmock_build_include_dirs}>"
-    $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>)
+    "$<INSTALL_INTERFACE:$<INSTALL_PREFIX>/${CMAKE_INSTALL_INCLUDEDIR}>")
 endif()
 
 ########################################################################
diff --git a/googletest/CMakeLists.txt b/googletest/CMakeLists.txt
index 2ac9aa0..9ee7940 100644
--- a/googletest/CMakeLists.txt
+++ b/googletest/CMakeLists.txt
@@ -138,10 +138,10 @@
 if (DEFINED CMAKE_VERSION AND NOT "${CMAKE_VERSION}" VERSION_LESS "2.8.11")
   target_include_directories(gtest SYSTEM INTERFACE
     "$<BUILD_INTERFACE:${gtest_build_include_dirs}>"
-    $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>)
+    "$<INSTALL_INTERFACE:$<INSTALL_PREFIX>/${CMAKE_INSTALL_INCLUDEDIR}>")
   target_include_directories(gtest_main SYSTEM INTERFACE
     "$<BUILD_INTERFACE:${gtest_build_include_dirs}>"
-    $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>)
+    "$<INSTALL_INTERFACE:$<INSTALL_PREFIX>/${CMAKE_INSTALL_INCLUDEDIR}>")
 endif()
 target_link_libraries(gtest_main PUBLIC gtest)