Variable name with space in solution file

[igorbanfi]

I noticed that solution files with variables that include space character are read incorrectly with SCIPreadSol.

Example code to reproduce.

#include <scip/scip.h>
#include <scip/scipdefplugins.h>

using namespace std;

int
main(
     int args,
     char ** argv
     )
{

   SCIP* scip = NULL;

   SCIP_CALL( SCIPcreate(&scip) );

   SCIP_CALL( SCIPincludeDefaultPlugins(scip) );

   SCIP_CALL( SCIPcreateProb(scip, "test", NULL, NULL, NULL, NULL, NULL, NULL, NULL) );

   SCIP_CALL( SCIPsetObjsense(scip, SCIP_OBJSENSE_MAXIMIZE) );

   SCIP_VAR* var;
   std::string var_name = "x   1";

   SCIP_CALL( SCIPcreateVar(scip, & var, var_name.c_str(), 0.0, 1.0, 1.0, SCIP_VARTYPE_BINARY, TRUE, FALSE, NULL, NULL, NULL, NULL, NULL) );

   SCIP_CALL( SCIPaddVar(scip, var) );

   SCIP_CALL( SCIPsolve(scip) );

   FILE *  file;
   if ((file = fopen("Solution.sol", "w")) != nullptr)
   {
      SCIP_CALL( SCIPprintBestSol(scip, file, FALSE) );
   }

   SCIP_CALL( SCIPfreeReoptSolve( scip ) );

   SCIP_CALL( SCIPreadSol(scip, "Solution.sol") );
   
   return EXIT_SUCCESS;
}

Output when trying to read the generated Solution.sol:

unknown variable <x> in line 2 of solution file <Solution.sol>
  (further unknown variables are ignored)