Include the prerelease version in the protobuf_VERSION

cmake/CMakeLists.txt

@@ -44,17 +44,24 @@ string(REGEX REPLACE        "${protobuf_AC_INIT_REGEX}" "\\2"
 string(REGEX REPLACE        "${protobuf_AC_INIT_REGEX}" "\\3"
     protobuf_CONTACT        "${protobuf_AC_INIT_LINE}")
 # Parse version tweaks
-set(protobuf_VERSION_REGEX "^([0-9]+)\\.([0-9]+)\\.([0-9]+).*$")
+set(protobuf_VERSION_REGEX "^([0-9]+)\\.([0-9]+)\\.([0-9]+)-?(.*)$")
 string(REGEX REPLACE     "${protobuf_VERSION_REGEX}" "\\1"
   protobuf_VERSION_MAJOR "${protobuf_VERSION_STRING}")
 string(REGEX REPLACE     "${protobuf_VERSION_REGEX}" "\\2"
   protobuf_VERSION_MINOR "${protobuf_VERSION_STRING}")
 string(REGEX REPLACE     "${protobuf_VERSION_REGEX}" "\\3"
   protobuf_VERSION_PATCH "${protobuf_VERSION_STRING}")
+string(REGEX REPLACE     "${protobuf_VERSION_REGEX}" "\\4"
+  protobuf_VERSION_PRERELEASE "${protobuf_VERSION_STRING}")
+
 # Package version
 set(protobuf_VERSION
   "${protobuf_VERSION_MAJOR}.${protobuf_VERSION_MINOR}.${protobuf_VERSION_PATCH}")
 
+if(protobuf_VERSION_PRERELEASE)
+  set(protobuf_VERSION "${protobuf_VERSION}-${protobuf_VERSION_PRERELEASE}")
+endif()
+
 if(protobuf_VERBOSE)
   message(STATUS "Configuration script parsing status [")
   message(STATUS "  Description : ${protobuf_DESCRIPTION}")