On empty dumps: detect if source db is empty too

plugins/localdump/mysql.sh

@@ -13,7 +13,8 @@
 # 2022-02-14  ah     v2.0  rewrite with class like functions
 # 2022-02-18  ah     v2.1  WIP: added counters
 # 2022-03-17         v2.2  WIP: add lines with prefix __DB__
-# 2022-03-21         v2.3  Check if the created dump contains "insert"
+# 2022-03-21         v2.3  Check if the created dump contains "insert" 
+# 2022-03-24         v2.4  On empty dumps: detect if source db is empty too
 # ================================================================================
 
 if [ -z "$LOCALDUMP_LOADED" ]; then
@@ -94,9 +95,19 @@ function mysql.db.dump(){
   fetchrc >/dev/null
 
   if [ $myrc -eq 0 ]; then
-        zgrep -iE "(CREATE|INSERT)" "$_dumpfile" >/dev/null
-        fetchrc >/dev/null
-        test $myrc -ne 0 && echo "ERROR: no data - the dump doesn't contain any CREATE or INSERT statement."
+        if ! zgrep -iE "(CREATE|INSERT)" "$_dumpfile" >/dev/null
+        then
+          typeset -i local _iTables
+          _iTables=$( mysql --skip-column-names --batch -e "use $_dbname; show tables ;" | wc -l )
+          if [ $_iTables -eq 0 ];
+          then
+            echo -n "NO DATA in database"
+          else
+            echo "ERROR: no data - the dump doesn't contain any CREATE or INSERT statement."
+            # force an error
+            false; fetchrc >/dev/null
+          fi
+        fi
   fi
 
   test $myrc -eq 0 && mysql_COUNT_DUMPS+=1