Revert "Revert "uses: properly handle untapped fo…

…rmulae in recursive dependency expansion""

This reverts commit dc9819b86c60b5c6fd10373ff318d8ef60f97d52.

Library/Homebrew/cmd/uses.rb

@@ -47,7 +47,6 @@ module Homebrew
 
     uses = formulae.select do |f|
       used_formulae.all? do |ff|
-        begin
         if recursive
           deps = f.recursive_dependencies do |dependent, dep|
             if dep.recommended?
@@ -57,6 +56,12 @@ module Homebrew
             elsif dep.build?
               Dependency.prune unless includes.include?("build?")
             end
+
+            # If a tap isn't installed, we can't find the dependencies of one
+            # its formulae, and an exception will be thrown if we try.
+            if dep.is_a?(TapDependency) && !dep.tap.installed?
+              Dependency.keep_but_prune_recursive_deps
+            end
           end
           reqs = f.recursive_requirements do |dependent, req|
             if req.recommended?
@@ -86,10 +91,6 @@ module Homebrew
         reqs.any? do |req|
           req.name == ff.name || [ff.name, ff.full_name].include?(req.default_formula)
         end
-        rescue FormulaUnavailableError
-          # Silently ignore this case as we don't care about things used in
-          # taps that aren't currently tapped.
-        end
       end
     end
 

Library/Homebrew/dependency.rb

@@ -175,7 +175,7 @@ class TapDependency < Dependency
   attr_reader :tap
 
   def initialize(name, tags = [], env_proc = DEFAULT_ENV_PROC, option_names = [name.split("/").last])
-    @tap = name.rpartition("/").first
+    @tap = Tap.fetch(name.rpartition("/").first)
     super(name, tags, env_proc, option_names)
   end
 

Library/Homebrew/test/dependency_test.rb

@@ -118,6 +118,11 @@ class DependencyTests < Homebrew::TestCase
 end
 
 class TapDependencyTests < Homebrew::TestCase
+  def test_tap
+    dep = TapDependency.new("foo/bar/dog")
+    assert_equal Tap.new("foo", "bar"), dep.tap
+  end
+
   def test_option_names
     dep = TapDependency.new("foo/bar/dog")
     assert_equal %w[dog], dep.option_names