Add Rugged.valid_full_oid? helper method

Author: brianmario

ext/rugged/rugged.c

@@ -109,6 +109,28 @@ static VALUE rb_git_features(VALUE self)
 	return ret_arr;
 }
 
+/*
+ *  call-seq:
+ *    Rugged.valid_full_oid?(oid) -> true or false
+ *
+ *  Checks to see if a string contains a full 40-character sha1.
+ *
+ *    Rugged.valid_full_oid?('d8786bfc97485e8d7b19b21fb88c8ef1f199fc3f')
+ *    #=> true
+ */
+static VALUE rb_git_valid_full_oid(VALUE self, VALUE hex)
+{
+	git_oid oid;
+
+	Check_Type(hex, T_STRING);
+	int errorcode = git_oid_fromstr(&oid, StringValueCStr(hex));
+	if (errorcode < 0) {
+		return Qfalse;
+	} else {
+		return Qtrue;
+	}
+}
+
 /*
  *  call-seq:
  *    Rugged.hex_to_raw(oid) -> raw_buffer
@@ -421,6 +443,7 @@ void Init_rugged(void)
 
 	rb_define_module_function(rb_mRugged, "libgit2_version", rb_git_libgit2_version, 0);
 	rb_define_module_function(rb_mRugged, "features", rb_git_features, 0);
+	rb_define_module_function(rb_mRugged, "valid_full_oid?", rb_git_valid_full_oid, 1);
 	rb_define_module_function(rb_mRugged, "hex_to_raw", rb_git_hex_to_raw, 1);
 	rb_define_module_function(rb_mRugged, "raw_to_hex", rb_git_raw_to_hex, 1);
 	rb_define_module_function(rb_mRugged, "minimize_oid", rb_git_minimize_oid, -1);

test/lib_test.rb

@@ -44,6 +44,12 @@ def test_features
     assert features.is_a? Array
   end
 
+  def test_valid_full_oid
+    assert Rugged.valid_full_oid?("ce08fe4884650f067bd5703b6a59a8b3b3c99a09")
+    refute Rugged.valid_full_oid?("nope")
+    refute Rugged.valid_full_oid?("ce08fe4884650f067bd5703b6a59a8b3b3c99a0")
+  end
+
   def test_hex_to_raw_oid
     raw = Rugged::hex_to_raw("ce08fe4884650f067bd5703b6a59a8b3b3c99a09")
     b64raw = Base64.encode64(raw).strip