tap: support --full even if installed

Makes `tap` re-runnable and unshallows when requested with `--full`.
Tapping with a different URL raises an exception.

The homebrew/core tap cannot be untapped with `untap` so running
`brew tap --full homebrew/core` is now a built-in way to get a full
clone of this tap without resorting to workarounds.

Closes #17.

Signed-off-by: ilovezfs <ilovezfs@icloud.com>

1 files changed, 29 insertions, 0 deletions

diff --git a/Library/Homebrew/exceptions.rb b/Library/Homebrew/exceptions.rb
index 79cfac012..dfd60549d 100644
--- a/Library/Homebrew/exceptions.rb
+++ b/Library/Homebrew/exceptions.rb
@@ -119,6 +119,23 @@ class TapUnavailableError < RuntimeError
   end
 end
 
+class TapRemoteMismatchError < RuntimeError
+  attr_reader :name
+  attr_reader :expected_remote
+  attr_reader :actual_remote
+
+  def initialize(name, expected_remote, actual_remote)
+    @name = name
+    @expected_remote = expected_remote
+    @actual_remote = actual_remote
+
+    super <<-EOS.undent
+      Tap #{name} remote mismatch.
+      #{expected_remote} != #{actual_remote}
+    EOS
+  end
+end
+
 class TapAlreadyTappedError < RuntimeError
   attr_reader :name
 
@@ -131,6 +148,18 @@ class TapAlreadyTappedError < RuntimeError
   end
 end
 
+class TapAlreadyUnshallowError < RuntimeError
+  attr_reader :name
+
+  def initialize(name)
+    @name = name
+
+    super <<-EOS.undent
+      Tap #{name} already a full clone.
+    EOS
+  end
+end
+
 class TapPinStatusError < RuntimeError
   attr_reader :name, :pinned