beesh: fix search for suggested revision number

This change reduces code, avoids a call to an external programm
and does quoting correctly for all metacharacters

We don't need to restore extglob to its former value, as this
function doesn't return and we are about to exit

src/beesh.sh.in

@@ -141,17 +141,11 @@ function check_rebuild() {
         return 0
     fi
 
-    beefile_dir=${beefile%/*}
     eval $(${BEEVERSION} "${beefile}")
 
     beefile_pattern="${PKGFULLNAME}-${PKGFULLVERSION}"
-    beefile_pattern=${beefile_pattern//+/\\+} # replace all + with \+
-    beefile_pattern=${beefile_pattern//./\\.} # replace all . with \.
-
-    beefile_max=$(for bf in $(ls ${beefile%/*}/${beefile_pattern}*.bee ${BEE_BEEDIR}/${beefile_pattern}*.bee 2>/dev/null |\
-                              grep -E "/${beefile_pattern}-[0-9]+.bee") ; do
-                      echo "${bf}"
-                  done | ${BEESORT} | tail -1)
+    shopt -s extglob
+    beefile_max=$( ls "${beefile%/*}/${beefile_pattern}"-+([0-9]).bee "${BEE_BEEDIR}/${beefile_pattern}"-+([0-9]).bee 2>/dev/null | ${BEESORT} | tail -1)
 
     eval $(${BEEVERSION} ${beefile_max})
     print_warning "please increase revision number to $((PKGREVISION + 1))"