create: allow --set-name and --set-version

Closes Homebrew/homebrew#10873.
Closes Homebrew/homebrew#14401.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>

Library/Homebrew/cmd/create.rb

@@ -2,18 +2,32 @@ require 'formula'
 require 'blacklist'
 
 module Homebrew extend self
+
+  # Create a formula from a tarball URL
   def create
+
+    # Allow searching MacPorts or Fink.
     if ARGV.include? '--macports'
       exec "open", "http://www.macports.org/ports.php?by=name&substr=#{ARGV.next}"
     elsif ARGV.include? '--fink'
       exec "open", "http://pdb.finkproject.org/pdb/browse.php?summary=#{ARGV.next}"
-    elsif ARGV.named.empty?
-      raise UsageError
-    else
+    end
+
+    raise UsageError if ARGV.named.empty?
+
+    # Ensure that the cache exists so we can fetch the tarball
     HOMEBREW_CACHE.mkpath
-      paths = ARGV.named.map do |url|
+
+    url = ARGV.named.first # Pull the first (and only) url from ARGV
+
+    version = ARGV.next if ARGV.include? '--set-version'
+    name = ARGV.next if ARGV.include? '--set-name'
+
     fc = FormulaCreator.new
+    fc.name = name
+    fc.version = version
     fc.url = url
+
     fc.mode = if ARGV.include? '--cmake'
       :cmake
     elsif ARGV.include? '--autotools'
@@ -27,6 +41,8 @@ module Homebrew extend self
       fc.path = Formula.path fc.name
     end
 
+    # Don't allow blacklisted formula, or names that shadow aliases,
+    # unless --force is specified.
     unless ARGV.force?
       if msg = blacklisted?(fc.name)
         raise "#{fc.name} is blacklisted for creation.\n#{msg}\nIf you really want to create this formula use --force."
@@ -41,12 +57,11 @@ module Homebrew extend self
           EOS
       end
     end
-        fc.generate
-        fc.path
-      end
-      puts "Please `brew audit "+paths.collect{|p|p.basename(".rb")}*" "+"` before submitting, thanks."
-      exec_editor *paths
-    end
+
+    fc.generate!
+
+    puts "Please `brew audit #{fc.name}` before submitting, thanks."
+    exec_editor fc.path
   end
 
   def __gets
@@ -59,22 +74,26 @@ class FormulaCreator
   attr :url
   attr :sha1
   attr :name, true
+  attr :version, true
   attr :path, true
   attr :mode, true
 
   def url= url
     @url = url
-    path = Pathname.new url
+    path = Pathname.new(url)
+    if @name.nil?
       /(.*?)[-_.]?#{path.version}/.match path.basename
       @name = $1
       @path = Formula.path $1 unless $1.nil?
+    else
+      @path = Formula.path name
+    end
+    if @version.nil?
+      @version = Pathname.new(url).version
+    end
   end
 
-  def version
-    Pathname.new(url).version
-  end
-
-  def generate
+  def generate!
     raise "#{path} already exists" if path.exist?
 
     require 'digest'
@@ -83,8 +102,6 @@ class FormulaCreator
     if version.nil?
       opoo "Version cannot be determined from URL."
       puts "You'll need to add an explicit 'version' to the formula."
-    else
-      puts "Version detected as #{version}."
     end
 
     unless ARGV.include? "--no-fetch" and version
@@ -105,6 +122,9 @@ class FormulaCreator
     class #{Formula.class_s name} < Formula
       homepage ''
       url '#{url}'
+    <% unless  version.nil? %>
+      version '#{version}'
+    <% end  %>
       sha1 '#{sha1}'
 
     <% if  mode == :cmake %>