Attempt to sanitize the database identifiers, fix #11285

Removing the quote and semicolon characters should be sufficient to prevent breaking out of the shell command, but this may need reviewed by someone more knowlegeable in shell scripting.

handlers/mysql.in

@@ -255,6 +255,9 @@ then
 
    for db in $databases
    do
+      # Sanitize database name
+      db=$(echo $db | tr -d \'\;)
+
       DUMP_BASE="$MYSQLDUMP $defaultsfile $sqldumpoptions"
 
       # Dumping structure and data