MDEV-25444: mysql --binary-mode is not able to replay some mysqlbinlo…

…g outputs

This is a documentation-only patch to refine the description of
binary mode for the mariadb client.

Reviewed By:
============
Andrei Elkin <andrei.elkin@mariadb.com>

client/mysql.cc

@@ -1698,11 +1698,14 @@ static struct my_option my_long_options[] =
     &opt_default_auth, &opt_default_auth, 0,
    GET_STR, REQUIRED_ARG, 0, 0, 0, 0, 0, 0},
   {"binary-mode", 0,
-   "By default, ASCII '\\0' is disallowed and '\\r\\n' is translated to '\\n'. "
-   "This switch turns off both features, and also turns off parsing of all client"
-   "commands except \\C and DELIMITER, in non-interactive mode (for input "
-   "piped to mysql or loaded using the 'source' command). This is necessary "
-   "when processing output from mysqlbinlog that may contain blobs.",
+   "Binary mode allows certain character sequences to be processed as data "
+   "that would otherwise be treated with a special meaning by the parser. "
+   "Specifically, this switch turns off parsing of all client commands except "
+   "\\C and DELIMITER in non-interactive mode (i.e., when binary mode is "
+   "combined with either 1) piped input, 2) the --batch mysql option, or 3) "
+   "the 'source' command). Also, in binary mode, occurrences of '\\r\\n' and "
+   "ASCII '\\0' are preserved within strings, whereas by default, '\\r\\n' is "
+   "translated to '\\n' and '\\0' is disallowed in user input.",
    &opt_binary_mode, &opt_binary_mode, 0, GET_BOOL, NO_ARG, 0, 0, 0, 0, 0, 0},
   { 0, 0, 0, 0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0}
 };

man/mysql.1

@@ -206,7 +206,14 @@ option\&.
 .\" binary-mode option: mysql
 \fB\-\-binary\-mode\fR
 .sp
-By default, ASCII '\e0' is disallowed and '\er\en' is translated to '\en'\&. This switch turns off both features, and also turns off parsing of all client commands except \eC and DELIMITER, in non-interactive mode (for input piped to mysql or loaded using the 'source' command)\&. This is necessary when processing output from mysqlbinlog that may contain blobs\&.
+Binary mode allows certain character sequences to be processed as data that
+would otherwise be treated with a special meaning by the parser\&.
+Specifically, this switch turns off parsing of all client commands except \eC
+and DELIMITER in non-interactive mode (i\&.e\&., when binary mode is combined
+with either 1) piped input, 2) the --batch mysql option, or 3) the 'source'
+command)\&. Also, in binary mode, occurrences of '\er\en' and ASCII '\e0' are
+preserved within strings, whereas by default, '\er\en' is translated to '\en'
+and '\e0' is disallowed in user input\&.
 .RE
 .sp
 .RS 4