discardOverridden does not work

[jihb]

Suppose there is the following css code:

.selector {
  margin-top: 3px;
  margin-top: 5px\0;
}

After being Compiled with cssnano, the output is:

.selector {
  margin-top: 5px\0;
}

the top one will be discard~

so I try to set 'preset' property like this:

require('cssnano')({
  preset: [
   'default', {
     discardOverridden: false
   }
  ]
})

but it does not work , so how can I solve this problem？

[alexander-akait]

bug, need fix, feel free to send a PR

[jihb]

When I disabled the option 'mergeLonghand' , the bug was disappear~

so it is a bug of 'postcss-merge-longhand'~

[alexander-akait]

@jihb yep, feel free to send a PR with fix

[stegano]

Is this an issue resolved?

[Akiyamka]

Look like discardOverridden now broken

[ludofischer]

The issue is stranger than I thought, it looks like discard-overridden is correctly excluded from the plugin list if you set discardOverriden: false, so it might not be it that's causing the folding.

[ludofischer]

Look like discardOverridden now broken

As far I know, it was never meant to work across rules, only for declarations inside the same rule.

[fvsadem]

This optimisation doesn't work at all...