While performing SAST scanning using Cppcheck against source code of
commit 81196469, several code vulnerabilities were found.

Fix following issues:

1. Parameters of `snprintf` function are incorrect.

   Cppcheck error:

       client/mysql_plugin.c:1228: error: snprintf format string requires 6 parameters but only 5 are given.

   It is due to commit 630d7229 introduced option `--lc-messages-dir`
   in the bootstrap command. However the parameter was not even given
   in the `snprintf` after changing the format string.

   Fix:
   Restructure the code logic and correct the function parameters for
   `snprintf`.

2. Null pointer is used in a `snprintf` which could cause a crash.

   Cppcheck error:

       extra/mariabackup/xbcloud.cc:2534: error: Null pointer dereference

   The code intended to print the swift_project name, if the
   opt_swift_project_id is NULL but opt_swift_project is not NULL.
   However the parameter of `snprintf` was mistakenly using
   `opt_swift_project_id`.

   Fix:
   Change to use the correct string from `opt_swift_project`.

3. Potential double release of a memory

   Cppcheck error:

       plugin/auth_pam/testing/pam_mariadb_mtr.c:69: error: Memory pointed to by 'resp' is freed twice.

   A pointer `resp` is reused and allocated new memory after it has been
   freed. However, `resp` was not set to NULL after freed.
   Potential double release of the same pointer if the call back
   function doesn't allocate new memory for `resp` pointer.

   Fix:
   Set the `resp` pointer to NULL after the first free() to make sure
   the same address is not freed twice.

All new code of the whole pull request, including one or several files
that are either new files or modified ones, are contributed under the
BSD-new license. I am contributing on behalf of my employer Amazon Web
Services, Inc.

This patch is the result of running
run-clang-tidy -fix -header-filter=.* -checks='-*,modernize-use-equals-default' .

Code style changes have been done on top. The result of this change
leads to the following improvements:

1. Binary size reduction.
* For a -DBUILD_CONFIG=mysql_release build, the binary size is reduced by
  ~400kb.
* A raw -DCMAKE_BUILD_TYPE=Release reduces the binary size by ~1.4kb.

2. Compiler can better understand the intent of the code, thus it leads
   to more optimization possibilities. Additionally it enabled detecting
   unused variables that had an empty default constructor but not marked
   so explicitly.

   Particular change required following this patch in sql/opt_range.cc

   result_keys, an unused template class Bitmap now correctly issues
   unused variable warnings.

   Setting Bitmap template class constructor to default allows the compiler
   to identify that there are no side-effects when instantiating the class.
   Previously the compiler could not issue the warning as it assumed Bitmap
   class (being a template) would not be performing a NO-OP for its default
   constructor. This prevented the "unused variable warning".

Fixing a few problems relealed by UBSAN in type_float.test

- multiplication overflow in dtoa.c

- uninitialized Field::geom_type (and Field::srid as well)

- Wrong call-back function types used in combination with SHOW_FUNC.
  Changes in the mysql_show_var_func data type definition were not
  properly addressed all around the code by the following commits:
    b4ff64568c88ab3ce559e7bd39853d9cbf86704a
    18feb62feeb833494d003615861b9c78ec008a90
    0ee879ff8ac1b80cd9a963015344f5698a81f309

  Adding a helper SHOW_FUNC_ENTRY() function and replacing
  all mysql_show_var_func declarations using SHOW_FUNC
  to SHOW_FUNC_ENTRY, to catch mysql_show_var_func in the future
  at compilation time.

Add a test related to the Encrypted Key File by following instructions in kb example
https://mariadb.com/kb/en/file-key-management-encryption-plugin/#creating-the-key-file

Reviewed by Daniel Black (with minor formatting and re-org of duplicate
close(f) calls).

This reverts commit cee7175b79a22c29a82ef328aba208f90afcea86.