I've give a look to the code and found this:
suppose you have custom field with ID 32 defined as DATE, when Mantis draw the inputs standard logic creates 3 inputs named as follow:
custom_field_32_year
custom_field_32_month
custom_field_32_day
The logic used to hide custom fields works ok, but the logic to show failed because on configuration is saved 'custom_field_32'.
My workaround is detect CF type, and if is of DATE type, add ALWAYS _year, to string that will be saved on CONFIG.
I've give a look to the code and found this: suppose you have custom field with ID 32 defined as DATE, when Mantis draw the inputs standard logic creates 3 inputs named as follow: custom_field_32_year custom_field_32_month custom_field_32_day
The logic used to hide custom fields works ok, but the logic to show failed because on configuration is saved 'custom_field_32'.
My workaround is detect CF type, and if is of DATE type, add ALWAYS _year, to string that will be saved on CONFIG.