1 files changed, 62 insertions, 22 deletions

diff --git a/Library/Homebrew/cmd/uninstall.rb b/Library/Homebrew/cmd/uninstall.rb
index 8bcfc31fb..d4a64c505 100644
--- a/Library/Homebrew/cmd/uninstall.rb
+++ b/Library/Homebrew/cmd/uninstall.rb
@@ -1,11 +1,15 @@
-#:  * `uninstall`, `rm`, `remove` [`--force`] <formula>:
+#:  * `uninstall`, `rm`, `remove` [`--force`] [`--ignore-dependencies`] <formula>:
 #:    Uninstall <formula>.
 #:
 #:    If `--force` is passed, and there are multiple versions of <formula>
 #:    installed, delete all installed versions.
+#:
+#:    If `--ignore-dependencies` is passed, uninstalling won't fail, even if
+#:    formulae depending on <formula> would still be installed.
 
 require "keg"
 require "formula"
+require "diagnostic"
 require "migrator"
 
 module Homebrew
@@ -14,38 +18,50 @@ module Homebrew
   def uninstall
     raise KegUnspecifiedError if ARGV.named.empty?
 
-    if !ARGV.force?
-      ARGV.kegs.each do |keg|
-        keg.lock do
-          puts "Uninstalling #{keg}... (#{keg.abv})"
-          keg.unlink
-          keg.uninstall
-          rack = keg.rack
-          rm_pin rack
-
-          if rack.directory?
-            versions = rack.subdirs.map(&:basename)
-            verb = versions.length == 1 ? "is" : "are"
-            puts "#{keg.name} #{versions.join(", ")} #{verb} still installed."
-            puts "Remove all versions with `brew uninstall --force #{keg.name}`."
-          end
-        end
-      end
-    else
-      ARGV.named.each do |name|
+    kegs_by_rack = if ARGV.force?
+      Hash[ARGV.named.map do |name|
         rack = Formulary.to_rack(name)
+        [rack, rack.subdirs.map { |d| Keg.new(d) }]
+      end]
+    else
+      ARGV.kegs.group_by(&:rack)
+    end
+
+    if should_check_for_dependents?
+      all_kegs = kegs_by_rack.values.flatten(1)
+      return if check_for_dependents all_kegs
+    end
+
+    kegs_by_rack.each do |rack, kegs|
+      if ARGV.force?
         name = rack.basename
 
         if rack.directory?
           puts "Uninstalling #{name}... (#{rack.abv})"
-          rack.subdirs.each do |d|
-            keg = Keg.new(d)
+          kegs.each do |keg|
             keg.unlink
             keg.uninstall
           end
         end
 
         rm_pin rack
+      else
+        kegs.each do |keg|
+          keg.lock do
+            puts "Uninstalling #{keg}... (#{keg.abv})"
+            keg.unlink
+            keg.uninstall
+            rack = keg.rack
+            rm_pin rack
+
+            if rack.directory?
+              versions = rack.subdirs.map(&:basename)
+              verb = versions.length == 1 ? "is" : "are"
+              puts "#{keg.name} #{versions.join(", ")} #{verb} still installed."
+              puts "Remove all versions with `brew uninstall --force #{keg.name}`."
+            end
+          end
+        end
       end
     end
   rescue MultipleVersionsInstalledError => e
@@ -61,6 +77,30 @@ module Homebrew
     end
   end
 
+  def should_check_for_dependents?
+    # --ignore-dependencies, to be consistent with install
+    return false if ARGV.include?("--ignore-dependencies")
+    return false if ARGV.homebrew_developer?
+    true
+  end
+
+  def check_for_dependents(kegs)
+    return false unless result = Keg.find_some_installed_dependents(kegs)
+
+    requireds, dependents = result
+
+    msg = "Refusing to uninstall #{requireds.join(", ")} because "
+    msg << (requireds.count == 1 ? "it is" : "they are")
+    msg << " required by #{dependents.join(", ")}, which "
+    msg << (dependents.count == 1 ? "is" : "are")
+    msg << " currently installed."
+    ofail msg
+    print "You can override this and force removal with "
+    puts "`brew uninstall --ignore-dependencies #{requireds.map(&:name).join(" ")}`."
+
+    true
+  end
+
   def rm_pin(rack)
     Formulary.from_rack(rack).unpin
   rescue