* lib/fileutils.rb (FileUtils.chmod{,_R}): Enhance the symbolic

mode parser to support the permission symbols u/g/o and multiple
  actions as defined in SUS, so that chmod("g=o+w", file) works as
  expected.  Invalid symbolic modes are now rejected with
  ArgumentError.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41782 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,9 +1,15 @@
-Fri Jul  5 01:23:33 2013  Akinori MUSHA  <knu@iDaemons.org>
+Fri Jul  5 02:14:00 2013  Akinori MUSHA  <knu@iDaemons.org>
 
 	* lib/fileutils.rb (FileUtils#symbolic_modes_to_i): Fix the wrong
 	  character class [+-=], which happened to match all desired
 	  characters but also match undesired characters.
 
+	* lib/fileutils.rb (FileUtils.chmod{,_R}): Enhance the symbolic
+	  mode parser to support the permission symbols u/g/o and multiple
+	  actions as defined in SUS, so that chmod("g=o+w", file) works as
+	  expected.  Invalid symbolic modes are now rejected with
+	  ArgumentError.
+
 Fri Jul  5 00:25:39 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* lib/mkmf.rb (have_framework): allow header file to check.

lib/fileutils.rb

@@ -868,62 +868,78 @@ module FileUtils
   OPT_TABLE['install'] = [:mode, :preserve, :noop, :verbose]
 
   def user_mask(target)  #:nodoc:
-    mask = 0
+    target.each_char.inject(0) do |mask, chr|
-    target.each_byte do |byte_chr|
+      case chr
-      case byte_chr.chr
       when "u"
-          mask |= 04700
+        mask | 04700
       when "g"
-          mask |= 02070
+        mask | 02070
       when "o"
-          mask |= 01007
+        mask | 01007
       when "a"
-          mask |= 07777
+        mask | 07777
+      else
+        raise ArgumentError, "invalid `who' symbol in file mode: #{chr}"
       end
     end
-    mask
   end
   private_module_function :user_mask
 
-  def mode_mask(mode, path)  #:nodoc:
+  def apply_mask(mode, user_mask, op, mode_mask)
-    mask = 0
+    case op
-    mode.each_byte do |byte_chr|
+    when '='
-      case byte_chr.chr
+      (mode & ~user_mask) | (user_mask & mode_mask)
+    when '+'
+      mode | (user_mask & mode_mask)
+    when '-'
+      mode & ~(user_mask & mode_mask)
+    end
+  end
+  private_module_function :apply_mask
+
+  def symbolic_modes_to_i(mode_sym, path)  #:nodoc:
+    mode_sym.split(/,/).inject(File.stat(path).mode & 07777) do |current_mode, clause|
+      target, *actions = clause.split(/([=+-])/)
+      raise ArgumentError, "invalid file mode: #{mode_sym}" if actions.empty?
+      target = 'a' if target.empty?
+      user_mask = user_mask(target)
+      actions.each_slice(2) do |op, perm|
+        need_apply = op == '='
+        mode_mask = (perm || '').each_char.inject(0) do |mask, chr|
+          case chr
           when "r"
-          mask |= 0444
+            mask | 0444
           when "w"
-          mask |= 0222
+            mask | 0222
           when "x"
-          mask |= 0111
+            mask | 0111
           when "X"
-          mask |= 0111 if FileTest::directory? path
+            if FileTest.directory? path
-        when "s"
+              mask | 0111
-          mask |= 06000
+            else
-        when "t"
-          mask |= 01000
-      end
-    end
               mask
             end
-  private_module_function :mode_mask
+          when "s"
-
+            mask | 06000
-  def symbolic_modes_to_i(modes, path)  #:nodoc:
+          when "t"
-    current_mode = (File.stat(path).mode & 07777)
+            mask | 01000
-    modes.split(/,/).inject(0) do |mode, mode_sym|
+          when "u", "g", "o"
-      mode_sym = "a#{mode_sym}" if mode_sym =~ %r!^[=+-]!
+            if mask.nonzero?
-      target, mode = mode_sym.split %r![=+-]!
+              current_mode = apply_mask(current_mode, user_mask, op, mask)
-      user_mask = user_mask(target)
-      mode_mask = mode_mask(mode ? mode : "", path)
-
-      case mode_sym
-        when /=/
-          current_mode &= ~(user_mask)
-          current_mode |= user_mask & mode_mask
-        when /\+/
-          current_mode |= user_mask & mode_mask
-        when /-/
-          current_mode &= ~(user_mask & mode_mask)
             end
+            need_apply = false
+            copy_mask = user_mask(chr)
+            (current_mode & copy_mask) / (copy_mask & 0111) * (user_mask & 0111)
+          else
+            raise ArgumentError, "invalid `perm' symbol in file mode: #{chr}"
+          end
+        end
+
+        if mode_mask.nonzero? || need_apply
+          current_mode = apply_mask(current_mode, user_mask, op, mode_mask)
+        end
+      end
+      current_mode
     end
   end
   private_module_function :symbolic_modes_to_i

test/fileutils/test_fileutils.rb

@@ -932,6 +932,12 @@ class TestFileUtils
     check_singleton :chmod
 
     touch 'tmp/a'
+    chmod "u=wrx,g=rx,o=x", 'tmp/a'
+    assert_equal 0751, File.stat('tmp/a').mode & 07777
+    chmod "g+w-x", 'tmp/a'
+    assert_equal 0761, File.stat('tmp/a').mode & 07777
+    chmod "o+r,g=o+w,o-r,u-o", 'tmp/a' # 761 => 763 => 773 => 771 => 671
+    assert_equal 0671, File.stat('tmp/a').mode & 07777
     chmod "u=wrx,g=,o=", 'tmp/a'
     assert_equal 0700, File.stat('tmp/a').mode & 0777
     chmod "u=rx,go=", 'tmp/a'
@@ -956,6 +962,26 @@ class TestFileUtils
       assert_equal 0500, File.stat('tmp/a').mode & 07777
     end
 
+    assert_raises_with_message(ArgumentError, /invalid\b.*\bfile mode/) {
+      chmod "a", 'tmp/a'
+    }
+
+    assert_raises_with_message(ArgumentError, /invalid\b.*\bfile mode/) {
+      chmod "x+a", 'tmp/a'
+    }
+
+    assert_raises_with_message(ArgumentError, /invalid\b.*\bfile mode/) {
+      chmod "u+z", 'tmp/a'
+    }
+
+    assert_raises_with_message(ArgumentError, /invalid\b.*\bfile mode/) {
+      chmod ",+x", 'tmp/a'
+    }
+
+    assert_raises_with_message(ArgumentError, /invalid\b.*\bfile mode/) {
+      chmod "755", 'tmp/a'
+    }
+
   end if have_file_perm?