Merge pull request #1082 from alyssais/uninstall_dependancy_error

uninstall: refuse when dependents still installed

1 files changed, 27 insertions, 0 deletions

diff --git a/Library/Homebrew/formula.rb b/Library/Homebrew/formula.rb
index ab05548a8..5434d87c2 100644
--- a/Library/Homebrew/formula.rb
+++ b/Library/Homebrew/formula.rb
@@ -1337,6 +1337,13 @@ class Formula
     end
   end
 
+  # Clear caches of .racks and .installed.
+  # @private
+  def self.clear_cache
+    @racks = nil
+    @installed = nil
+  end
+
   # An array of all racks currently installed.
   # @private
   def self.racks
@@ -1459,6 +1466,26 @@ class Formula
     recursive_dependencies.reject(&:build?)
   end
 
+  # Returns a list of formulae depended on by this formula that aren't
+  # installed
+  def missing_dependencies(hide: nil)
+    hide ||= []
+    missing_dependencies = recursive_dependencies do |dependent, dep|
+      if dep.optional? || dep.recommended?
+        tab = Tab.for_formula(dependent)
+        Dependency.prune unless tab.with?(dep)
+      elsif dep.build?
+        Dependency.prune
+      end
+    end
+
+    missing_dependencies.map!(&:to_formula)
+    missing_dependencies.select! do |d|
+      hide.include?(d.name) || d.installed_prefixes.empty?
+    end
+    missing_dependencies
+  end
+
   # @private
   def to_hash
     hsh = {