FindMatlab: Tolerate empty version log file

Modules/FindMatlab.cmake

@@ -725,7 +725,7 @@ function(matlab_get_version_from_matlab_run matlab_binary_program matlab_list_ve
   file(REMOVE "${_matlab_temporary_folder}/matlabVersionLog.cmaketmp")
 
   set(index -1)
-  string(FIND ${_matlab_version_from_cmd} "ans" index)
+  string(FIND "${_matlab_version_from_cmd}" "ans" index)
   if(index EQUAL -1)
 
     if(MATLAB_FIND_DEBUG)
@@ -735,7 +735,7 @@ function(matlab_get_version_from_matlab_run matlab_binary_program matlab_list_ve
   else()
     set(matlab_list_of_all_versions_tmp)
 
-    string(SUBSTRING ${_matlab_version_from_cmd} ${index} -1 substring_ans)
+    string(SUBSTRING "${_matlab_version_from_cmd}" ${index} -1 substring_ans)
     string(
       REGEX MATCHALL "ans[\r\n\t ]*=[\r\n\t ]*'?([0-9]+(\\.[0-9]+)?)"
       matlab_versions_regex