/\\section{/ { oldline=$0
               if ( oldline ~ /}/ ) {
                   lt=gensub(".*{([^}]+)}.*","\\1","g",oldline)
               } else {
                   lt=gensub(".*{(.*)","\\1","g",oldline) 
                   getline tmp
                   while ( tmp !~  "}" ) {
                       lt=lt "\n" tmp
                       getline tmp
                   }
                   lt=lt "\n" gensub("}.*","","g",tmp)
               }
               getline
               while ( $0 !~ /\\sectionmark/ ) {
                   getline
               }
               printf("\\section[%s]{%s%s}\n",lt,lt,$0)
               getline
             }
! /\\section{/ { print }