A cleanup for MDEV-17088 Provide tools to encode/decode mysql-encoded file system names

- Load and convert the entire input file at once,
  rather than reading string-by-string using fgets().
  This change makes it possible to convert from UCS2, UTF16, UTF32 data.
- Adding the --delimiter command, to treat the specified
  characters as delimiters rather than data to convert.
  Useful in combination with `-f filename` or `-t filename`.
  The delimiter characters are not converted,
  they are copied from the input to the output as is.
- Adding diagnostics with line number and position if:
  * an illegal input byte sequence was found
  * a character cannot be converted to the target character set

3 files changed, 6 insertions, 0 deletions

diff --git a/mysql-test/std_data/mariadb-conv/file01.utf16.txt b/mysql-test/std_data/mariadb-conv/file01.utf16.txt
new file mode 100644
index 00000000000..1ff100e48a1
--- /dev/null
+++ b/mysql-test/std_data/mariadb-conv/file01.utf16.txt
diff --git a/mysql-test/std_data/mariadb-conv/file01.utf8.txt b/mysql-test/std_data/mariadb-conv/file01.utf8.txt
new file mode 100644
index 00000000000..cc065b71877
--- /dev/null
+++ b/mysql-test/std_data/mariadb-conv/file01.utf8.txt
@@ -0,0 +1,3 @@
+aaa
+xxxяяяxxx
+bbb
diff --git a/mysql-test/std_data/mariadb-conv/file02.latin1.txt b/mysql-test/std_data/mariadb-conv/file02.latin1.txt
new file mode 100644
index 00000000000..28648e6f1e1
--- /dev/null
+++ b/mysql-test/std_data/mariadb-conv/file02.latin1.txt
@@ -0,0 +1,3 @@
+aaa
+xxx���xxx
+bbb