implement formulary#find_with_priority

Library/Homebrew/cmd/info.rb

@@ -29,7 +29,11 @@ module Homebrew
       ARGV.named.each_with_index do |f, i|
         puts unless i == 0
         begin
-          info_formula Formulary.factory(f)
+          if f.include?("/") || File.exist?(f)
+            info_formula Formulary.factory(f)
+          else
+            info_formula Formulary.find_with_priority(f)
+          end
         rescue FormulaUnavailableError
           # No formula with this name, try a blacklist lookup
           if (blacklist = blacklisted?(f))

Library/Homebrew/extend/ARGV.rb

@@ -13,7 +13,13 @@ module HomebrewArgvExtension
 
   def formulae
     require "formula"
-    @formulae ||= (downcased_unique_named - casks).map { |name| Formulary.factory(name, spec) }
+    @formulae ||= (downcased_unique_named - casks).map do |name|
+      if name.include?("/") || File.exist?(name)
+        Formulary.factory(name, spec)
+      else
+        Formulary.find_with_priority(name, spec)
+      end
+    end
   end
 
   def resolved_formulae

Library/Homebrew/formulary.rb

@@ -250,9 +250,9 @@ class Formulary
     Pathname.new("#{HOMEBREW_LIBRARY}/Formula/#{name.downcase}.rb")
   end
 
-  def self.tap_paths(name)
+  def self.tap_paths(name, taps=Dir["#{HOMEBREW_LIBRARY}/Taps/*/*/"])
     name = name.downcase
-    Dir["#{HOMEBREW_LIBRARY}/Taps/*/*/"].map do |tap|
+    taps.map do |tap|
       Pathname.glob([
         "#{tap}Formula/#{name}.rb",
         "#{tap}HomebrewFormula/#{name}.rb",
@@ -260,4 +260,22 @@ class Formulary
       ]).detect(&:file?)
     end.compact
   end
+
+  def self.find_with_priority(ref, spec=:stable)
+    possible_pinned_tap_formulae = tap_paths(ref, Dir["#{HOMEBREW_LIBRARY}/PinnedTaps/*/*/"]).map(&:realpath)
+    if possible_pinned_tap_formulae.size > 1
+      raise TapFormulaAmbiguityError.new(ref, possible_pinned_tap_formulae)
+    elsif possible_pinned_tap_formulae.size == 1
+      selected_formula = factory(possible_pinned_tap_formulae.first, spec)
+      if core_path(ref).file?
+        opoo <<-EOS.undent
+          #{ref} is provided by core, but is now shadowed by #{selected_formula.full_name}.
+          To refer to the core formula, use Homebrew/homebrew/#{ref} instead.
+        EOS
+      end
+      selected_formula
+    else
+      factory(ref, spec)
+    end
+  end
 end