wL#5625: Deprecate mysqlbinlog options --base64-output=always and --base64-output

Adds deprecation warning for the mysqlbinlog options
--base64-output=always and --base64-output.
A warning is printed when the flags are used,
and also when running mysqlbinlog --help.

client/mysqlbinlog.cc

@@ -1010,10 +1010,11 @@ static struct my_option my_long_options[] =
    "row-based events; 'decode-rows' decodes row events into commented SQL "
    "statements if the --verbose option is also given; 'auto' prints base64 "
    "only when necessary (i.e., for row-based events and format description "
-   "events); 'always' prints base64 whenever possible. 'always' is for "
-   "debugging only and should not be used in a production system. If this "
-   "argument is not given, the default is 'auto'; if it is given with no "
-   "argument, 'always' is used.",
+   "events); 'always' prints base64 whenever possible. 'always' is "
+   "deprecated, will be removed in a future version, and should not be used "
+   "in a production system.  --base64-output with no 'name' argument is "
+   "equivalent to --base64-output=always and is also deprecated.  If no "
+   "--base64-output[=name] option is given at all, the default is 'auto'.",
    &opt_base64_output_mode_str, &opt_base64_output_mode_str,
    0, GET_STR, OPT_ARG, 0, 0, 0, 0, 0, 0},
   /*
@@ -2024,6 +2025,13 @@ int main(int argc, char** argv)
 
   if (opt_base64_output_mode == BASE64_OUTPUT_UNSPEC)
     opt_base64_output_mode= BASE64_OUTPUT_AUTO;
+  if (opt_base64_output_mode == BASE64_OUTPUT_ALWAYS)
+    warning("The --base64-output=always flag and the --base64-output flag "
+            "(with '=MODE' omitted), are deprecated. "
+            "The output generated when these flags are used cannot be "
+            "parsed by mysql 5.6.0 and later. "
+            "The flags will be removed in a future version. "
+            "Please use --base64-output=auto instead.");
 
   my_set_max_open_files(open_files_limit);
 

mysql-test/r/mysqlbinlog.result

@@ -879,3 +879,7 @@ ROLLBACK /* added by mysqlbinlog */;
 /*!50003 SET COMPLETION_TYPE=@OLD_COMPLETION_TYPE*/;
 End of 5.0 tests
 End of 5.1 tests
+# Expect deprecation warning.
+WARNING: The --base64-output=always flag and the --base64-output flag (with '=MODE' omitted), are deprecated. The output generated when these flags are used cannot be parsed by mysql 5.6.0 and later. The flags will be removed in a future version. Please use --base64-output=auto instead.
+# Expect deprecation warning again.
+WARNING: The --base64-output=always flag and the --base64-output flag (with '=MODE' omitted), are deprecated. The output generated when these flags are used cannot be parsed by mysql 5.6.0 and later. The flags will be removed in a future version. Please use --base64-output=auto instead.

mysql-test/t/mysqlbinlog.test

@@ -487,3 +487,18 @@ diff_files $MYSQLTEST_VARDIR/tmp/mysqlbinlog.warn $MYSQLTEST_VARDIR/tmp/mysqlbin
 # Cleanup for this part of test
 remove_file $MYSQLTEST_VARDIR/tmp/mysqlbinlog.warn.empty;
 remove_file $MYSQLTEST_VARDIR/tmp/mysqlbinlog.warn;
+
+#
+# WL#5625: Deprecate mysqlbinlog options --base64-output=always and --base64-output
+#
+
+--echo # Expect deprecation warning.
+--exec $MYSQL_BINLOG --base64-output=always std_data/master-bin.000001 > /dev/null 2> $MYSQLTEST_VARDIR/tmp/mysqlbinlog.warn
+--cat_file $MYSQLTEST_VARDIR/tmp/mysqlbinlog.warn
+
+--echo # Expect deprecation warning again.
+--exec $MYSQL_BINLOG --base64-output std_data/master-bin.000001 > /dev/null 2> $MYSQLTEST_VARDIR/tmp/mysqlbinlog.warn
+--cat_file $MYSQLTEST_VARDIR/tmp/mysqlbinlog.warn
+
+# Clean up this part of the test.
+--remove_file $MYSQLTEST_VARDIR/tmp/mysqlbinlog.warn