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 *'.

1 files changed, 8 insertions, 3 deletions

diff --git a/client/mysqlshow.c b/client/mysqlshow.c
index 2b0cae6dc98..a89f4eb1dd2 100644
--- a/client/mysqlshow.c
+++ b/client/mysqlshow.c
@@ -289,7 +289,7 @@ are shown.");
 
 
 static my_bool
-get_one_option(const struct my_option *opt, char *argument,
+get_one_option(const struct my_option *opt, const char *argument,
                const char *filename __attribute__((unused)))
 {
   switch(opt->id) {
@@ -301,10 +301,15 @@ get_one_option(const struct my_option *opt, char *argument,
       argument= (char*) "";			/* Don't require password */
     if (argument)
     {
-      char *start=argument;
+      /*
+        One should not really change the argument, but we make an
+        exception for passwords
+      */
+      char *start= (char*) argument;
       my_free(opt_password);
       opt_password=my_strdup(PSI_NOT_INSTRUMENTED, argument, MYF(MY_FAE));
-      while (*argument) *argument++= 'x';		/* Destroy argument */
+      while (*argument)
+        *(char*) argument++= 'x';               /* Destroy argument */
       if (*start)
 	start[1]=0;				/* Cut length of argument */
       tty_password= 0;