Bug Report: NULL or null in column comment changes default value

Copy of tracker Issue 3673.

What exact steps will reproduce the problem?
1. Create a column (I tested this with BIT(1) and TINYINT)
2. Set the column default value to 0, as a number, or another acceptable value, like 1.
3. In the comment for that column add either "NULL" or "null" (quotes not necessary) somewhere in the comment.

What was the expected output?
Expected the default value to remain the correct, unchanged value.

What happened instead?
If "NULL" was entered the default value changes to NULL.
If "null" was entered the default value changes to CURRENT_TIMESTAMP.



HeidiSQL revision: 9.1.0.4867
MySQL Server version: 5.6.15

operating system : Windows 7 x64 Service Pack 1 build 7601
system language : Dutch
processors : 8x Intel(R) Core(TM) i7-4770 CPU @ 3.40GHz
physical memory : 4176/7864 MB (free/total)
free disk space : (C:) 14,89 GB
display mode : 1920x1080, 32 bit
process id : $64c
allocated memory : 100,22 MB
largest free block : 8185,55 GB
executable : heidisql.exe
exec. date/time : 2014-11-11 20:38
version : 9.1.0.4867