BUG: Fix for string comparison when one string is empty.

Modules/CMakeImportBuildSettings.cmake

@@ -19,7 +19,7 @@ MACRO(CMAKE_IMPORT_BUILD_SETTINGS SETTINGS_FILE)
 
     # Check the build tool.
     STRING(COMPARE NOTEQUAL
-           "${CMAKE_BUILD_TOOL}" "${CMAKE_BUILD_SETTING_BUILD_TOOL}"
+           "x${CMAKE_BUILD_TOOL}" "x${CMAKE_BUILD_SETTING_BUILD_TOOL}"
            CMAKE_BUILD_TOOL_MISMATCH)
 
     IF(CMAKE_BUILD_SETTING_BUILD_TOOL MATCHES "^msdev$")
@@ -33,36 +33,36 @@ MACRO(CMAKE_IMPORT_BUILD_SETTINGS SETTINGS_FILE)
     # project is not a C++ project, and doesn't need a matching compiler.
     IF(CMAKE_BUILD_SETTING_CXX_COMPILER)
       STRING(COMPARE NOTEQUAL
-             "${CMAKE_CXX_COMPILER}" "${CMAKE_BUILD_SETTING_CXX_COMPILER}"
+             "x${CMAKE_CXX_COMPILER}" "x${CMAKE_BUILD_SETTING_CXX_COMPILER}"
              CMAKE_CXX_COMPILER_MISMATCH)
     ENDIF(CMAKE_BUILD_SETTING_CXX_COMPILER)
 
     # Check the C build variation flags.
     STRING(COMPARE NOTEQUAL
-           "${CMAKE_C_FLAGS_DEBUG}" "${CMAKE_BUILD_SETTING_C_FLAGS_DEBUG}"
+           "x${CMAKE_C_FLAGS_DEBUG}" "x${CMAKE_BUILD_SETTING_C_FLAGS_DEBUG}"
            CMAKE_C_FLAGS_DEBUG_MISMATCH)
     STRING(COMPARE NOTEQUAL
-           "${CMAKE_C_FLAGS_RELEASE}" "${CMAKE_BUILD_SETTING_C_FLAGS_RELEASE}"
+           "x${CMAKE_C_FLAGS_RELEASE}" "x${CMAKE_BUILD_SETTING_C_FLAGS_RELEASE}"
            CMAKE_C_FLAGS_RELEASE_MISMATCH)
     STRING(COMPARE NOTEQUAL
-           "${CMAKE_C_FLAGS_MINSIZEREL}" "${CMAKE_BUILD_SETTING_C_FLAGS_MINSIZEREL}"
+           "x${CMAKE_C_FLAGS_MINSIZEREL}" "x${CMAKE_BUILD_SETTING_C_FLAGS_MINSIZEREL}"
            CMAKE_C_FLAGS_MINSIZEREL_MISMATCH)
     STRING(COMPARE NOTEQUAL
-           "${CMAKE_C_FLAGS_RELWITHDEBINFO}" "${CMAKE_BUILD_SETTING_C_FLAGS_RELWITHDEBINFO}"
+           "x${CMAKE_C_FLAGS_RELWITHDEBINFO}" "x${CMAKE_BUILD_SETTING_C_FLAGS_RELWITHDEBINFO}"
            CMAKE_C_FLAGS_RELWITHDEBINFO_MISMATCH)
 
     # Check the C++ build variation flags.
     STRING(COMPARE NOTEQUAL
-           "${CMAKE_CXX_FLAGS_DEBUG}" "${CMAKE_BUILD_SETTING_CXX_FLAGS_DEBUG}"
+           "x${CMAKE_CXX_FLAGS_DEBUG}" "x${CMAKE_BUILD_SETTING_CXX_FLAGS_DEBUG}"
            CMAKE_CXX_FLAGS_DEBUG_MISMATCH)
     STRING(COMPARE NOTEQUAL
-           "${CMAKE_CXX_FLAGS_RELEASE}" "${CMAKE_BUILD_SETTING_CXX_FLAGS_RELEASE}"
+           "x${CMAKE_CXX_FLAGS_RELEASE}" "x${CMAKE_BUILD_SETTING_CXX_FLAGS_RELEASE}"
            CMAKE_CXX_FLAGS_RELEASE_MISMATCH)
     STRING(COMPARE NOTEQUAL
-           "${CMAKE_CXX_FLAGS_MINSIZEREL}" "${CMAKE_BUILD_SETTING_CXX_FLAGS_MINSIZEREL}"
+           "x${CMAKE_CXX_FLAGS_MINSIZEREL}" "x${CMAKE_BUILD_SETTING_CXX_FLAGS_MINSIZEREL}"
            CMAKE_CXX_FLAGS_MINSIZEREL_MISMATCH)
     STRING(COMPARE NOTEQUAL
-           "${CMAKE_CXX_FLAGS_RELWITHDEBINFO}" "${CMAKE_BUILD_SETTING_CXX_FLAGS_RELWITHDEBINFO}"
+           "x${CMAKE_CXX_FLAGS_RELWITHDEBINFO}" "x${CMAKE_BUILD_SETTING_CXX_FLAGS_RELWITHDEBINFO}"
            CMAKE_CXX_FLAGS_RELWITHDEBINFO_MISMATCH)
 
     # Check the build type.
@@ -70,7 +70,7 @@ MACRO(CMAKE_IMPORT_BUILD_SETTINGS SETTINGS_FILE)
     IF(WIN32)
       IF(NOT CMAKE_IMPORT_BUILD_SETTINGS_IMPORTING_FROM_MS_STUDIO)
         STRING(COMPARE NOTEQUAL
-               "${CMAKE_BUILD_TYPE}" "${CMAKE_BUILD_SETTING_BUILD_TYPE}"
+               "x${CMAKE_BUILD_TYPE}" "x${CMAKE_BUILD_SETTING_BUILD_TYPE}"
                CMAKE_BUILD_TYPE_MISMATCH)
       ENDIF(NOT CMAKE_IMPORT_BUILD_SETTINGS_IMPORTING_FROM_MS_STUDIO)
     ENDIF(WIN32)