Bug#16046140 BIN/MYSQLD_SAFE: TEST: ARGUMENT EXPECTED

Some shell interpreters do not support '-e' test
primary to construct conditions.

man test 1 (on S10)
...skip...
-e file True if file exists. (Not available in sh.)
...skip...

Hence, check for the existence of a file using
'-e' might result in a syntax error on such
shell programs.

Fixed by replacing it by '-f'.

scripts/mysqld_safe.sh

@@ -393,7 +393,7 @@ then
   log_notice "Logging to '$err_log'."
   logging=file
 
-  if [ ! -e "$err_log" ]; then                  # if error log already exists,
+  if [ ! -f "$err_log" ]; then                  # if error log already exists,
     touch "$err_log"                            # we just append. otherwise,
     chmod "$fmode" "$err_log"                   # fix the permissions here!
   fi
@@ -599,7 +599,7 @@ do
 
   eval_log_error "$cmd"
 
-  if [ $want_syslog -eq 0 -a ! -e "$err_log" ]; then
+  if [ $want_syslog -eq 0 -a ! -f "$err_log" ]; then
     touch "$err_log"                    # hypothetical: log was renamed but not
     chown $user "$err_log"              # flushed yet. we'd recreate it with
     chmod "$fmode" "$err_log"           # wrong owner next time we log, so set