Fix cmake build directory interference issue.

Author: madler

CMakeLists.txt

@@ -151,9 +151,13 @@ if(MINGW)
 endif(MINGW)
 
 add_library(zlib SHARED ${ZLIB_SRCS} ${ZLIB_DLL_SRCS} ${ZLIB_PUBLIC_HDRS} ${ZLIB_PRIVATE_HDRS})
-target_include_directories(zlib PUBLIC ${CMAKE_CURRENT_BINARY_DIR} ${CMAKE_CURRENT_SOURCE_DIR})
+target_include_directories(zlib PUBLIC
+    $<BUILD_INTERFACE:${CMAKE_CURRENT_BINARY_DIR}>
+    $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>)
 add_library(zlibstatic STATIC ${ZLIB_SRCS} ${ZLIB_PUBLIC_HDRS} ${ZLIB_PRIVATE_HDRS})
-target_include_directories(zlibstatic PUBLIC ${CMAKE_CURRENT_BINARY_DIR} ${CMAKE_CURRENT_SOURCE_DIR})
+target_include_directories(zlibstatic PUBLIC
+    $<BUILD_INTERFACE:${CMAKE_CURRENT_BINARY_DIR}>
+    $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>)
 set_target_properties(zlib PROPERTIES DEFINE_SYMBOL ZLIB_DLL)
 set_target_properties(zlib PROPERTIES SOVERSION 1)