Since options have `empty_values(true)` by default, so long as another valid flag
or option came after the option in question, clap would parse it as an empty value
incorrectly. This commit forces the user to explicitly add an empty value.
`--option "" --flag` is allowed
`--option --flag` is no longer allowed unless the user has *also* set `min_values(0)`
This commit also fixes an issue where `-o=` would be parsed as a value of `Some("=")`
instead of `Some("")`.
Closes#1105
OsStr recently gained unstable inherent methods with the same name. This rename
makes sure we don't call the inherent methods but the methods provided by this
extension trait.
The method `starts_with` as implemented for the `OsStrExt2` trait on
`OsStr` assumed that the needle given is shorter than the haystack. When
this is not the case, the method panics due to an attempted
out-of-bounds access on the byte representation of `self`. Problematic
if, say, an end-user gives us `"-"` and the library tries to see if that
starts with `"--"`.
Fortunately, slices already implement a `starts_with` method, and we can
delegate to it.
This *does* create a semantics change: if both `self` and the needle
have length 0, this implementation will return `true`, but the old
implementation would return `false`. Based on the test suite still
passing, acknowledging the vacuous truth doesn't seem to cause any
problems.
Fixes#410
This commit adds support for values separated by commas such as
--option=val1,val2,val3. It also includes support for uses
without the equals and shorts (both with and without)
--option=val1,val2
--option val1,val2
-oval1,val2
-o=val1,val2
-o val1,val2
Closes#348
