Slices are cleared and appended, should be overwritten

[pavelbazika]

Hi

I've a scenario, where at first configuration struct is loaded from config file and then envconfig is applied to overwrite some settings from environment variables, when they exist.

One of the fields in the config struct is a slice of string. When an environment variable for this slice exists, the slice is not replaced by value from the environment variable. Instead, resulting slice contains as many items as it was in config file set to empty string followed by environment variable value.

For example:

• original slice value from config file - ["foo"]
• environment variable value - "bar"
• slice after envconfig - ["", "bar"]

I guess the bug is in function setSliceField on line

envconfig/envconfig.go

Line 252 in e689cc5

slice := reflect.MakeSlice(value.Type(), value.Len(), value.Cap())

There shouldn't be value.Len() but 0 in my opinion.

Best Regards

Pavel

[vrischmann]

Hi,

can you make a small test case which reproduces the problem ?

Also since you seem to have an idea of where the problem is I'd be happy to review and merge a PR.

[pavelbazika]

Ok, will do.

[pavelbazika]

#28