rewrite bash 4 ;;& operator (two step)

gitstatus.sh

@@ -26,17 +26,26 @@ num_conflicts=0
 num_untracked=0
 while IFS='' read -r line || [[ -n "$line" ]]; do
   status=${line:0:2}
-  while true
+  while [[ -n $status ]]
   do
     case "$status" in
+#two fixed character matches, loop finished
       \#\#) branch_line="${line/\.\.\./^}"; break ;;
-      ?M) ((num_changed++)); status=${status:0:1}"_" ;;
-      ?D) ((num_changed++)); status=${status:0:1}"_" ;;
-      U?) ((num_conflicts++)); break ;;
       \?\?) ((num_untracked++)); break ;;
-      \ ?) break ;;
+      U?) ((num_conflicts++)); break;;
-      *) ((num_staged++)); break ;;
+      ?U) ((num_conflicts++)); break;;
+      DD) ((num_conflicts++)); break;;
+      AA) ((num_conflicts++)); break;;
+#two character matches, first loop
+      ?M) ((num_changed++)) ;;
+      ?D) ((num_changed++)) ;;
+      ?\ ) ;;
+#single character matches, second loop
+      U) ((num_conflicts++)) ;;
+      \ ) ;;
+      *) ((num_staged++)) ;;
     esac
+    status=${status:0:-1}
   done
 done <<< "$gitstatus"