Added 'const' to arguments in get_one_option and find_typeset()

One should not change the program arguments!
This change also reduces warnings from the icc compiler.

Almost all changes are just syntax changes (adding const to
'get_one_option function' declarations).

Other changes:
- Added a few cast of 'argument' from 'const char*' to 'char *'. This
  was mainly in calls to 'external' functions we don't have control of.
- Ensure that all reset of 'password command line argument' are similar.
  (In almost all cases it was just adding a comment and a cast)
- In mysqlbinlog.cc and mysqld.cc there was a few cases that changed
  the command line argument. These places where changed to instead allocate
  the option in a MEM_ROOT to avoid changing the argument. Some of this
  code was changed to ensure that different programs did parsing the
  same way. Added a test case for the changes in mysqlbinlog.cc
- Changed a few variables that took their value from command line options
  from 'char *' to 'const char *'.

4 files changed, 13 insertions, 11 deletions

diff --git a/extra/mariabackup/innobackupex.cc b/extra/mariabackup/innobackupex.cc
index 9e95d2e6b16..e874890ad27 100644
--- a/extra/mariabackup/innobackupex.cc
+++ b/extra/mariabackup/innobackupex.cc
@@ -88,7 +88,7 @@ char *opt_ibx_incremental_history_name = NULL;
 char *opt_ibx_incremental_history_uuid = NULL;
 
 char *opt_ibx_user = NULL;
-char *opt_ibx_password = NULL;
+const char *opt_ibx_password = NULL;
 char *opt_ibx_host = NULL;
 char *opt_ibx_defaults_group = NULL;
 char *opt_ibx_socket = NULL;
@@ -731,7 +731,7 @@ indicates an error.\n");
 static
 my_bool
 ibx_get_one_option(const struct my_option *opt,
-                   char *argument, const char *)
+                   const char *argument, const char *)
 {
 	switch(opt->id) {
 	case '?':
diff --git a/extra/mariabackup/xbstream.cc b/extra/mariabackup/xbstream.cc
index c22c7cc8f39..3fe9d17d86e 100644
--- a/extra/mariabackup/xbstream.cc
+++ b/extra/mariabackup/xbstream.cc
@@ -90,7 +90,7 @@ static int get_options(int *argc, char ***argv);
 static int mode_create(int argc, char **argv);
 static int mode_extract(int n_threads, int argc, char **argv);
 static my_bool get_one_option(const struct my_option *opt,
-			      char *argument, const char *filename);
+			      const char *argument, const char *filename);
 
 int
 main(int argc, char **argv)
@@ -138,7 +138,8 @@ get_options(int *argc, char ***argv)
 	int ho_error;
 
 	if ((ho_error= handle_options(argc, argv, my_long_options,
-				      get_one_option))) {
+				      get_one_option)))
+        {
 		exit(EXIT_FAILURE);
 	}
 
@@ -191,7 +192,7 @@ set_run_mode(run_mode_t mode)
 
 static
 my_bool
-get_one_option(const struct my_option *opt, char *, const char *)
+get_one_option(const struct my_option *opt, const char *, const char *)
 {
 	switch (opt->id) {
 	case 'c':
diff --git a/extra/mariabackup/xtrabackup.cc b/extra/mariabackup/xtrabackup.cc
index b8cdf4cd9db..495c7d7e2fe 100644
--- a/extra/mariabackup/xtrabackup.cc
+++ b/extra/mariabackup/xtrabackup.cc
@@ -311,7 +311,7 @@ char *opt_incremental_history_name;
 char *opt_incremental_history_uuid;
 
 char *opt_user;
-char *opt_password;
+const char *opt_password;
 char *opt_host;
 char *opt_defaults_group;
 char *opt_socket;
@@ -1861,7 +1861,7 @@ check_if_param_set(const char *param)
 
 my_bool
 xb_get_one_option(const struct my_option *opt,
-		  char *argument, const char *)
+		  const char *argument, const char *)
 {
   switch(opt->id) {
   case 'h':
@@ -6348,9 +6348,10 @@ void handle_options(int argc, char **argv, char ***argv_server,
 
         if (opt_password)
         {
-          char *argument= opt_password;
-          char *start= argument;
-          opt_password= my_strdup(PSI_NOT_INSTRUMENTED, opt_password, MYF(MY_FAE));
+          char *argument= (char*) opt_password;
+          char *start= (char*) opt_password;
+          opt_password= my_strdup(PSI_NOT_INSTRUMENTED, opt_password,
+                                  MYF(MY_FAE));
           while (*argument)
             *argument++= 'x'; // Destroy argument
           if (*start)
diff --git a/extra/mariabackup/xtrabackup.h b/extra/mariabackup/xtrabackup.h
index 6376849430c..aff7d1cb287 100644
--- a/extra/mariabackup/xtrabackup.h
+++ b/extra/mariabackup/xtrabackup.h
@@ -144,7 +144,7 @@ extern char		*opt_incremental_history_name;
 extern char		*opt_incremental_history_uuid;
 
 extern char		*opt_user;
-extern char		*opt_password;
+extern const char	*opt_password;
 extern char		*opt_host;
 extern char		*opt_defaults_group;
 extern char		*opt_socket;