Use real directory paths in version.cmake (fixes gh #47)

Author: mhx

cmake/version.cmake

@@ -21,19 +21,22 @@ set(VERSION_HDR_FILE ${CMAKE_CURRENT_SOURCE_DIR}/include/dwarfs/version.h)
 
 execute_process(
   COMMAND git rev-parse --show-toplevel
-  OUTPUT_VARIABLE GIT_TOPLEVEL
+  OUTPUT_VARIABLE GIT_TOPLEVEL_RAW
   OUTPUT_STRIP_TRAILING_WHITESPACE ERROR_QUIET)
 
 execute_process(
   COMMAND git log --pretty=format:%h -n 1
   OUTPUT_VARIABLE PRJ_GIT_REV
   OUTPUT_STRIP_TRAILING_WHITESPACE ERROR_QUIET)
 
-if((NOT "${CMAKE_CURRENT_SOURCE_DIR}" STREQUAL "${GIT_TOPLEVEL}")
+get_filename_component(GIT_TOPLEVEL "${GIT_TOPLEVEL_RAW}" REALPATH)
+get_filename_component(REAL_SOURCE_DIR "${CMAKE_CURRENT_SOURCE_DIR}" REALPATH)
+
+if((NOT "${REAL_SOURCE_DIR}" STREQUAL "${GIT_TOPLEVEL}")
    OR ("${PRJ_GIT_REV}" STREQUAL ""))
   if(NOT EXISTS ${VERSION_SRC_FILE} OR NOT EXISTS ${VERSION_HDR_FILE})
-    message("CMAKE_CURRENT_SOURCE_DIR: ${CMAKE_CURRENT_SOURCE_DIR}")
-    message("GIT_TOPLEVEL: ${GIT_TOPLEVEL}")
+    message("REAL_SOURCE_DIR: ${REAL_SOURCE_DIR} (${CMAKE_CURRENT_SOURCE_DIR})")
+    message("GIT_TOPLEVEL: ${GIT_TOPLEVEL} (${GIT_TOPLEVEL_RAW})")
     message("PRJ_GIT_REV: ${PRJ_GIT_REV}")
     message(FATAL_ERROR "missing version files")
   endif()