Fix Document-attr in the C parser

Previously the comment-open marker was not included in the comment
returned from find_attr_comment.  This meant that normalization would
not strip the "*"s correctly leading to broken output.

Now the opening "*"s are included, but only when the Document-attr is on
the same line as the opening "/*" or on the line following the opening
"/*".

Fixes #271

Author: drbrain

History.rdoc

@@ -5,6 +5,7 @@
     yield and &block are present.  Pull request #281 by Victor Bilyk.
   * Fixed merging of rd-style and hash-style comments at the top of a file.
     Bug #266 by Zachary Scott.
+  * Fixed Document-attr in the C parser.  Bug #271 by Hanmac.
   * Removed duplicated condition in superclass fixup.  Pull request #282 by
     Benoit Daloze.
 

lib/rdoc/parser/c.rb

@@ -594,9 +594,10 @@ def find_attr_comment var_name, attr_name, read = nil, write = nil
                                             \s*#{attr_name}\s*,
                                             #{rw},.*?\)\s*;%xm then
                 $1
-              elsif @content =~ %r%Document-attr:\s#{attr_name}\s*?\n
-                                   ((?>.*?\*/))%xm then
-                $1
+              elsif @content =~ %r%(/\*.*?(?:\s*\*\s*)?)
+                                   Document-attr:\s#{attr_name}\s*?\n
+                                   ((?>(.|\n)*?\*/))%x then
+                "#{$1}\n#{$2}"
               else
                 ''
               end

test/test_rdoc_parser_c.rb

@@ -736,6 +736,47 @@ def test_find_alias_comment
     assert_equal "/*\n * comment\n */\n\n", comment.text
   end
 
+  def test_find_attr_comment_document_attr
+    parser= util_parser <<-C
+/*
+ * Document-attr: y
+ * comment
+ */
+    C
+
+    comment = parser.find_attr_comment nil, 'y'
+
+    assert_equal "/*\n * \n * comment\n */", comment.text
+  end
+
+  def test_find_attr_comment_document_attr_oneline
+    parser= util_parser <<-C
+/* Document-attr: y
+ * comment
+ */
+    C
+
+    comment = parser.find_attr_comment nil, 'y'
+
+    assert_equal "/* \n * comment\n */", comment.text
+  end
+
+  def test_find_attr_comment_document_attr_overlap
+    parser= util_parser <<-C
+/* Document-attr: x
+ * comment
+ */
+
+/* Document-attr: y
+ * comment
+ */
+    C
+
+    comment = parser.find_attr_comment nil, 'y'
+
+    assert_equal "/* \n * comment\n */", comment.text
+  end
+
   def test_find_class_comment
     @options.rdoc_include << File.dirname(__FILE__)